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PbSe Transimpedance Amplified Photodetector

  • PbSe Amplified Photoconductive Detector
  • Linear Response for 1.5 - 4.8 µm
  • Fixed Amplified Detector with Output up to 10 V



Detector with Ø1" Lens
Tube Attached to a 30 mm
Cage System

Power Supply Included with Detector

Related Items

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MIR Photodetector Selection Guidea
Item # (Detector) Wavelength
PDA10DT (InGaAs) 0.9 - 2.57 µm 1,000 kHz Yes
PDA10D2 (InGaAs) 0.9 - 2.6 µm 25,000 kHz No
PDA10PT (InAsSb) 1.0 - 5.8 µm 1,600 kHz Yes
PDA07P2 (InAsSb) 2.7 - 5.3 µm 9 MHz No
PDA20H (PbSe) 1.5 - 4.8 µm 10 kHz No
PDA10JT (HgCdTe) 2.0 - 5.4 µm 160 kHz Yes
PDAVJ8 (HgCdTe) 2.0 - 8.0 µm 100 MHz No
PDAVJ10 (HgCdTe) 2.0 - 10.6 µm 100 MHz No
PDAVJ5 (HgCdTe) 2.7 - 5.0 µm 1 MHz No
  • See the Cross Reference tab for our full selection of photodetectors.
Removable Internal SM1 Adapter
Click to Enlarge

Each detector has an internal SM05 and external SM1 thread and comes with an
attached SM1T1 Internal SM1 Adapter
and SM1RR Retaining Ring.


  • Detect Light from 1.5 - 4.8 µm
  • Higher Sensitivity and Better Linear Response in the Mid-IR (MIR) than Typical PIN Junction Photodiodes
  • Two 8-32 (M4) Tapped Mounting Holes for Post Mounting
  • Internally SM1 (1.035"-40) Threaded

Thorlabs' PDA20H(-EC) Amplified Detector, based on a photoconductive lead selenide (PbSe) detector element, is sensitive to mid-IR radiation (MIR) in the 1.5 - 4.8 µm spectral range. It detects light in a broader wavelength range, offers higher sensitivity, and provides better linear response in the MIR than typical PIN junction photodiodes.

The slim profile housing enables use in light paths with space constraints. All connections and controls are located perpendicular to the light path, providing increased accessibility. Amplification is provided by low noise transimpedance or voltage amplifiers that are capable of driving 50 Ω loads. Signal output is via a BNC connector. This photodetector is ideal for use with Thorlabs' passive low-pass filters; these filters have a 50 Ω input and a high-impedance output that allows them to be directly attached to high-impedance measurement devices such as an oscilloscope. Thorlabs offers a wide variety of BNC, BNC-to-SMA, and SMC cables, as well as a variety of BNC, SMA, and SMC adapters.

photo detector power supply
Click to Enlarge

The power supply is included with all of the detectors on this page.

The housing provides two 8-32 tapped mounting holes (M4 for the -EC model) for vertical or horizontal post mounting. The housing also features external SM1 (1.035"-40) threading and internal SM05 (0.535"-40) threading that are compatible with most Thorlabs SM1- and SM05-threaded accessories. Additionally, an internally threaded SM1 coupler is included with each detector. This allows convenient mounting of SM1 compatible accessories, optics, and cage assembly accessories. The internal SM05 threading is only suitable for mating to an externally threaded SM05 lens tube (components such as fiber adapters cannot be threaded onto the SM05 threading). Most SM1-threaded fiber adapters are compatible with this detector. However, the S120-FC internally SM1-threaded fiber adapter is not compatible with this detector. Externally SM1-threaded adapters should be mated to the included internally SM1-threaded adapter, while internally SM1-threaded adapters can be mated directly to the housing.

A ±12 V linear power supply that supports input voltages of 100, 120, and 230 VAC is included with each amplified photodetector. Replacement power supplies are available separately below. Due to limitations in the IC, the high-speed amplifier used in this device may become unstable, exhibiting oscillations or negative output if the linear power supply voltage is applied when the module is on. The unit should always be powered up using the power switch on the power supply or the unit itself. Hot plugging the unit is not recommended. Additionally, inhomogeneities at the edges of the active area of the detector can generate unwanted capacitance and resistance effects that distort the time-domain response of the photodetector output. Thorlabs therefore recommends that the incident light on the photodetector is well centered on the active area. The SM1 (1.035"-40) threading on the housing is ideally suited for mounting a Ø1" focusing lens or pinhole in front of the detector element.

Photoconductors vs. Photodiodes
Unlike PIN junction photodiodes, which generate a photocurrent when light is absorbed in the depleted region of the junction semiconductor, the photoconductive material in these devices exhibits a decrease in electrical resistance when illuminated with IR radiation. Photoconductive detectors typically have a very linear response when illuminated with IR radiation.

Usage Notes
Photoconductors function differently than typical PIN junction photodiodes. We recommend that an optical chopper be employed when using this detector with CW light, due to signal noise issues. PbS and PbSe detectors can be used at room temperature. However, temperature fluctuations will affect dark resistance, sensitivity, and response speeds.

If greater detector bandwidth is desired, Thorlabs manufactures HgCdTe and InAsSb detectors for the mid-IR that offer 160 kHz and 1600 kHz bandwidth, respectively.

Performance Specifications

Item #a Detector
Active Area Wavelength
Bandwidth Noise-Equivalent Power
Rise Time
PDA20H PbSe 4 mm2
(2 x 2 mm)
1.5 - 4.8 µm 1.5 x 103 V/W (Min)
3.0 x 103 V/W (Typ.)
(4.0 µm, 50 Ω Load)
0.2 Hz - 10 kHz 1.5 x 10-10 W/Hz1/2 35 µs
  • These detectors have AC coupled amplifiers.
  • NEP measurement parameters: 300 K blackbody source, 600 Hz chopping frequency, 635 Hz bandpass filter with 70 Hz noise bandwidth and 22 °C ambient temperature.

Gain Specifications

Item # Gain Type Gain with Hi-Z Load Gain with 50 Ω Load Output Voltage
with Hi-Z Load
Output Voltage
with 50 Ω Load
PDA20H Fixed 100X 50X ±10 V ±5 V

Note: Gain figures can also be expressed in units of Ω.

PDA Series Compact Design
PDA Series Design, scale in inches [mm].

Compact PDA & PDF Series Design

Thorlabs' Amplified Photodiode series features a slim design, which allows the detector access to the light path even between closely spaced optical elements.

The power supply input and the BNC output are located on the same outer edge of the package, further reducing the device thickness and allowing easier integration into tight optic arrangements. The PDA and PDF series detectors can fit into spaces as thin as 0.83" (21.1 mm) when the SM1 coupler is removed. With the SM1 coupler attached, the smallest width the detector can fit into is 1.03" (26.2 mm).

Additionally, the detectors have two tapped mounting holes perpendicular to each other so that the unit can be mounted in a horizontal or vertical orientation. This dual mounting feature offsets the fact that the cables protrude out the side of the package, thus requiring more free space above or alongside your beam path.

The switchable gain detectors feature an eight-position rotary gain switch (pictured below right) mounted on an outside edge perpendicular to the power supply and BNC output connections. The location of the gain switch allows for easy adjustments while the detector is mounted.

PDA detector Bottom and Side view

BNC Female Output (Photodetector)

BNC Female

0 - 10 V Output

PDA Male (Power Cables)

Pinout for PDA Power Cable

PDA Female (Photodetector)

Pinout for PDA Power Connector

PDA Series Mounting Options

The PDA series of amplified photodetectors are compatible with our entire line of lens tubes, TR series posts, and cage mounting systems. Because of the wide range of mounting options, the best method for mounting the housing in a given optical setup is not always obvious. The pictures and text in this tab will discuss some of the common mounting solutions. As always, our technical support staff is available for individual consultation.

amplified photodetector  amplified photodetector disassembled amplified photodetector close up
Picture of a PDA series photodetector as it will look when unpackaged. Picture of a PDA series photodetector with the included SM1T1 and its retaining ring removed from the front of the housing. Thorlabs' DET series photodetectors feature the same mounting options. A close up picture of the front of the PDA10A2 photodetector. The internal SM1 threading on the SM1T1 adapter and internal SM05 threading on the photodetector housing can be seen in this image.

TR Series Post (Ø1/2" Posts) System

The PDA housing can be mounted vertically or horizontally on a TR Series Post using the threaded holes for 8-32 (M4 on metric versions). Select PDA housings feature universally threaded holes for both 8-32 and M4 threads.

 mounted amplified photodetector vertical  mounted amplified photodetector horizontal
PDA series photodetector mounted vertically on a TR series post. In this configuration, the output and power cables (PDA series) are oriented vertically and away from the optic table, facilitating a neater optical setup. PDA series photodetector mounted horizontally on a TR series post. In this configuration, the on/off switch is conveniently oriented on the top of the detector.

Lens Tube System

Each PDA housing includes a detachable Ø1" Optic Mount (SM1T1) that allows for Ø1" (Ø25.4 mm) optical components, such as optical filters and lenses, to be mounted along the axis perpendicular to the center of the photosensitive region. The maximum thickness of an optic that can be mounted in the SM1T1 is 0.1" (2.8 mm). For thicker Ø1" (Ø25.4 mm) optics or for any thickness of Ø0.5" (Ø12.7 mm) optics, remove the SM1T1 from the front of the detector and place (must be purchased separately) an SM1 or SM05 series lens tube, respectively, on the front of the detector.

The SM1 and SM05 threadings on the PDA photodetector housing make it compatible with our SM lens tube system and accessories. Two particularly useful accessories include the SM-threaded irises and the SM-compatible IR and visible alignment tools. Also available are fiber optic adapters for use with connectorized fibers.

 Lens tube mounted amplified photodetector
PDA series photodetector mounted onto a Ø1" Slotted Lens Tube, which is housing a focusing optic. The lens tube is attached to a 30 mm cage system via a CP33 SM1-Threaded 30 mm Cage Plate. This arrangement allows easy access for optic adjustment and signal alignment.

Cage System

The simplest method for attaching the PDA photodetector housing to a cage plate is to remove the SM1T1 that is attached to the front of the PDA and use the external SM1 threads. A cage plate, such as the CP33 30 mm cage plate, can be directly attached to the SM1 threads. Then the retaining ring, included with the SM1T1, can be threaded using a spanner wrench into the CP33 to ensure the cage plate is tightened to the desired location and square with the photodetector housing. 

This method for attaching the PDA photodetector housing to a cage plate does not allow much freedom in determining the orientation of the photodetector; however, it has the benefit of not needing an adapter piece, and it allows the diode to be as close as possible to the cage plate, which can be important in setups where the light is divergent. As a side note, Thorlabs sells the SM05PD and SM1PD series of photodiodes that can be threaded into a cage plate so that the diode is flush with the front surface of the cage plate; however, the photodiode is unbiased.

For more freedom in choosing the orientation of the PDA photodetector housing when attaching it, an SM1T2 lens tube coupler can be purchased. In this configuration the SM1T1 is left on the detector and the SM1T2 is threaded into it. The exposed external SM1 threading is now deep enough to secure the detector to a CP33 cage plate in any orientation and lock it into place using one of the two locking rings on the ST1T2.

 photodetector with cage plate

photodetector with cage plate

photodetector with cage plate and spacer

This picture shows a PDA series photodetector attached to a CP33 cage plate after removing the SM1T1. The retaining ring from the SM1T1 was used to make the orientation of the detector square with the cage plate. These two pictures show a PDA series photodetector in a horizontal configuration. The top picture shows the detector directely coupled to a CP33 cage plate.
The bottom picture shows a PDA series photodetector attached to a CP33 cage plate using an SM1T2 adapter in addition to the SM1T1 that comes with the PDA series detector.

Although not pictured here, the PDA photodetector housing can be connected to a 16 mm cage system by purchasing an SM05T2. It can be used to connect the PDA photodetector housing to an SP02 cage plate.


The image below shows a Michelson Interferometer built entirely from parts available from Thorlabs. This application demonstrates the ease with which an optical system can be constructed using our lens tube, TR series post, and cage systems. 

 Michelson interferometer

The table below contains a part list for the Michelson Interferometer for use in the visible range. Follow the links to the pages for more information about the individual parts. 

Item # Quantity Description Item # Quantity Description
KC1 1 Mirror Mount CT1 1 1/2" Travel Translator
BB1-E02 2 Broadband Dielectric Laser Mirrors SM1D12 1 SM1 Threaded Lens Tube Iris
ER4 8 4" Cage Rods SM1L30C 1 SM1 3" Slotted Lens Tube
ER6 4 6" Cage Rods SM1V05 1 Ø1" Adjustable Length Lens Tube
CCM1-BS013 1 Cube-Mounted Beamsplitter CP08FP 1 30 mm Cage Plate for FiberPorts
BA2 1 Post Base (not shown in picture) PAF2-5A 1 FiberPort
TR2 1 Ø1/2" Post, 2" in Length P1-460B-FC-2 1 Single Mode Fiber Patch Cable
PH2 1 Ø1/2" Post Holder DET36A / PDA36A2 1 Biased / Amplified Photodiode Detector

PbS and PbSe Photoconductive Detectors

Lead Sulfide (PbS) and Lead Selenide (PbSe) photoconductive detectors are widely used in detection of infrared radiation from 1000 to 4800 nm. Unlike standard photodiodes, which produce a current when exposed to light, the electrical resistance of the photoconductive material is reduced when illuminated with light. Although PbS and PbSe detectors can be used at room temperature, temperature flucturations will affect dark resistance, sensitivity, and response speeds (see Temperature Considerations below).

Photoconductor Basic Model
Photoconductor Basic Schematic
Click to Enlarge

Theory of Operation

For photoconductive materials, incident light will cause the number of charge carriers in the active area to increase, thus decreasing the resistance of the detector. This change in resistance leads to a change in measured voltage, and hence, photosensitivity is expressed in units of V/W. An example operating circuit is shown to the right. Please note that the circuit depicted is not recommended for practical purposes since low frequency noise will be present.

The detection mechanism is based upon the conductivity of the thin film of the active area. The output signal of the detector with no incident light is defined by the following equation:

Photoconductor Basic Model

A change ΔVOUT then occurs due to a change ΔRDark in the resistance of the detector when light strikes the active area:

Photoconductor Basic Model

Frequency Response
Photoconductors must be used with a pulsed signal to obtain AC signals. Hence, an optical chopper should be employed when using these detectors with CW light. The detector responsivity (Rf) when using a chopper can be calculated using the equation below:

Photoconductor Responsivity

Here, fc is the chopping frequency, R0 is the response at 0 Hz, and τr is the detector rise time.

Effects of Chopping Frequency
The photoconductor signal will remain constant up to the time constant response limit. PbS and PbSe detectors have a typical 1/f noise spectrum (i.e., the noise decreases as chopping frequency increases), which has a profound impact on the time constant at lower frequencies.

The detector will exhibit lower responsivity at lower chopping frequencies. Frequency response and detectivity are maximized for

Photoconductor Chopper Equation

See Chapter 5 of the manuals for detector rise time values.

Temperature Considerations
These detectors consist of a thin film on a glass substrate. The effective shape and active area of the photoconductive surface varies considerably based upon the operating conditions, thus changing performance characteristics. Specifically, responsivity of the detector will change based upon the operating temperature.

Temperature characteristics of PbS and PbSe bandgaps have a negative coefficient, so cooling the detector shifts its spectral response range to longer wavelengths. For best results, operate the photodiode in a stable controlled environment.

Typical Photoconductor Amplifier Circuit

Due to the noise characteristic of a photoconductor, it is generally suited for AC coupled operation. The DC noise present with the applied bias will be too great at high bias levels, thus limiting the practicality of the detector. For this reason, IR detectors are normally AC coupled to limit the noise. A pre-amplifier is required to help maintain the stability and provide a large gain for the generated current signal.

Based on the schematic below, the op-amp will try to maintain point A to the input at B via the use of feedback. The difference between the two input voltages is amplified and provided at the output. It is also important to note the high pass filter that AC couples the input of the amplifier blocks any DC signal. In addition, the resistance of the load resistor (RLOAD) should be equal to the dark resistance of the detector to ensure maximum signal can be acquired. The supply voltage (+V) should be at a level where the SNR is acceptable and near unity. Some applications require higher voltage levels; as a result the noise will increase. The output voltage is derived as the following:

Photoconductor Amp Eq

Photoconductor Basic Amp Model
Amplifier Model

Signal to Noise Ratio
Since the detector noise is inversely proportional to the chopping frequency, the noise will be greater at low frequencies. The detector output signal is linear to increased bias voltage, but the noise shows little dependence on the bias at low levels. When a set bias voltage is reached, the detector noise will increase linearly with applied voltage. At high voltage levels, noise tends to increase exponentially, thus degrading the signal to noise ratio (SNR) further. To yield the best SNR, adjust the chopping frequency and bias voltage to an acceptable level.

Noise Equivalent Power
The noise equivalent power (NEP) is the generated RMS signal voltage generated when the signal to noise ratio is equal to one. This is useful, as the NEP determines the ability of the detector to detect low level light. In general, the NEP increases with the active area of the detector and is given by the following equation:

Photoconductor NEP

Here, S/N is the Signal to Noise Ratio, Δf is the Noise Bandwidth, and Incident Energy has units of W/cm2. For more information on NEP, please see Thorlabs' Noise Equivalent Power White Paper.

Dark Resistance
Dark Resistance is the resistance of the detector under no illumination. It is important to note that dark resistance will increase or decrease with temperature. Cooling the device will increase the dark resistance.

Detectivity (D) and Specific Detectivity (D*)
Detectivity (D) is another criteria used to evaluate the performance of the photodetector. Detectivity is a measure of sensitivity and is the reciprocal of NEP.

Photoconductor Detectivity

Higher values of detectivity indicate higher sensitivity, making the detector more suitable for detecting low light signals. Detectivity varies with the wavelength of the incident photon.

NEP of a detector depends upon the active area of the detector, which in essence will also affect detectivity. This makes it hard to compare the intrinsic properties of two detectors. To remove the dependence, Specific Detectivity (D*), which is not dependent on detector area, is used to evaluate the performance of the photodetector.

Photoconductor D*

Posted Comments:
Vasliliy Voropaev  (posted 2020-02-13 07:18:34.393)
Hello, please tell me the nature of the sensitivity of the receiver PDA20H in the range from 0.8 to 1.5 microns. If possible, could you provide a graph.
asundararaj  (posted 2020-02-21 08:29:43.0)
Thank you for contacting Thorlabs. While we do not have any data for the sensitivity of the unit below the specified region, we estimate that the sensitivity will follow the trend to 1 µm, below which it will drop further.
Italo Caliari  (posted 2019-03-22 10:25:06.877)
In the description of PDA30G says it is a PbSe detector and on the manual says is a PbS one.
mmcclure  (posted 2019-03-27 07:52:39.0)
Hello, thank you for contacting us about this error on our Portuguese-translated webpage, which has been corrected.
sepehr  (posted 2019-02-28 02:42:57.57)
Can this detector be used for laser pulses of 150 fs, 1 kHz rep rate, ~3-10KW? We have one of these which was purchased many years ago. Do they need re-calibration? It seems that the linearity and some specs are a bit off. please contact me.
llamb  (posted 2019-02-28 10:59:55.0)
Thank you for your feedback. The photodetectors will damage with your laser's high power pulses. I would recommend using ND filters or decreasing the power, if possible. I have reached out to you directly regarding calibration.
user  (posted 2018-12-20 22:46:41.703)
Can the Pb-Se and Pb-S detector be used to give absorption spectra like in a spectrometer?
YLohia  (posted 2018-12-24 10:01:58.0)
Hello, unfortunately, photoconductor based detectors cannot be used to provide absorption spectra like spectrometers, without significant test setup development involving gratings, slits, etc.
vasili.savitski  (posted 2018-08-27 13:11:53.547)
The output signal from the detector we purchased recently is negative. Is that normal?
YLohia  (posted 2018-08-29 12:14:42.0)
Hello, thank you for contacting Thorlabs. The output from this detector is AC coupled, so this behavior is expected.
nunop  (posted 2016-04-01 17:00:57.257)
I am interested in buying and using your PbS detector to measure solar infrared spectrum. I am aware of the need to chop the incoming light. For me it is not clear how the detection of the signal is done if no reference signal arising from the chopper is connected to the amplifier of the detector. Can you please advice on this question ? thanks in advance
besembeson  (posted 2016-04-05 12:46:04.0)
Response from Bweh at Thorlabs USA: The output signal that you get is an AC signal whose frequency is set by the frequency of the optical chopper (which could be up to the detector bandwidth). This is how the two are coupled. Note that the noise also decreases with higher chopping frequencies. We have some further discussion on using these detectors under the "Pbs/PbSe Tutorial" tab:
cbr  (posted 2015-01-30 14:43:08.87)
I would like to use this detector to perform an RIN measurement on a broadband long wavelength source. In order to do this, I need access to the DC component of the detected signal. According to the simplified circuit diagram, this can be obtained by attaching leads across Rload. Unfortunately, it is not possible to take the circuit board out of its enclosure without a fair bit of work to determine which resistor is Rload, so I would like to know which resistor this is or if it is even accessible. Thanks, -Chris
jlow  (posted 2015-02-03 04:00:48.0)
Response from Jeremy at Thorlabs: These IR sensors do not operate well at DC so they would not work well in a RIN measurement. I will contact you directly to discuss further about this.
mario.hauff  (posted 2014-01-17 09:05:15.213)
Dear Madam or Sir, please send linearity specs/diagrams for your PbS and PbSe detectors. What options could you offer for HP or BP filtering below 2um/ above 5um? Sincerely, Mario Hauff Electronic Wood Systems
jlow  (posted 2014-01-27 11:59:36.0)
Response from Jeremy at Thorlabs: The PDA20H and PDA30G detectors should be linear as long as the output voltage is <10V (for Hi-Z load). You can find our selection of bandpass filters at
hadmack  (posted 2013-07-08 18:36:56.007)
Can your PbSe and PbS detectors be used to make energy measurements for short pulses? Due to the slow response of these detectors can I effectively make an integrated measurement of a 1μsec duration pulse at 3000nm?
pbui  (posted 2013-08-08 16:29:00.0)
Response from Phong at Thorlabs: To determine if our detectors are compatible with your application, we would need to consider several factors, such as the laser's peak energy, average power, pulse length, and rep rate. It seems like you're interested in making absolute energy measurements. We offer other solutions that would be more appropriate. We will contact you directly to discuss the specifics of your application.
Laurie  (posted 2008-12-09 08:45:45.0)
Response from Laurie at Thorlabs to peter.rodrigo: Thank you for your interest in our photodetectors. The DET01CFC has an active area of 0.1 mm in diamter and a field of view of 48 deg. when using a ball-type lens with a diameter of 1.47 mm. The lens and diode are an integrated module built into the FC connector. The damage threshold is around 79 mW, but typical usage in the linear region should be below 1 mW. For the FPD510-F and FPD510-FV, the active areas are 0.3 mm in diameter and 0.4 mm in diameter, respectively. The entrance window is flat, and there is no focusing lens on these diodes. If you have additional questions please feel free to contact our technical support staff.
peter.rodrigo  (posted 2008-12-08 10:01:14.0)
hi. im trying to compare 2 detectors: FPD510 and DET01CFC. For either of the two, I couldnt find detector active area diameter, focusing lens type, max. incident power. I will use it for heterodyne interferometry where my optical signal which carries the beat frequency i aim to detect comes out of the FC/APC connector of the output port 3 of a Thorlabs fiber optic circulator. Im interested in getting optimal efficiency for coupling the ~1mW signal beam to the detector while avoiding saturation and also getting high SNR in the spectral analysis to extract the beat frequency in the range of 0 to 50MHz.Looking forward to you response-
technicalmarketing  (posted 2007-08-21 10:02:19.0)
The information you requested has been added to the "FPD510 Specs" tab. Thank you for taking the time to contribute to the improvement of our product presentations.
melsscal  (posted 2007-08-18 01:39:39.0)
Dear Sir, Following are not clear from your drawing datasheet of FPD-510FV: a) Signal Output connector : SMA male or SMA Female ? b) Supply Voltage Port connector : picture /banana female or what else what type ?

The following table lists Thorlabs' selection of photodiodes and photoconductive detectors. Item numbers in the same row contain the same detector element.

Photodetector Cross Reference
Wavelength Material Unmounted
150 - 550 nm GaP FGAP71 - SM05PD7A DET25K2 PDA25K2
200 - 1100 nm Si FDS010 - SM05PD2A
Si - - SM1PD2A - -
320 - 1100 nm Si - - - - PDA8A2
Si FD11A SM05PD3A PDF10A(/M)
Si - - - DET100A2 PDA100A2
340 - 1100 nm Si FDS10X10 - - - -
350 - 1100 nm Si FDS100
FDS100-CAL a
- SM05PD1A
Si FDS1010
FDS1010-CAL a
- -
400 - 1000 nm Si - - - - PDA015A(/M)
400 - 1100 nm Si FDS015 b - - - -
Si FDS025 b
FDS02 c
- - DET02AFC(/M)
400 - 1700 nm Si & InGaAs DSD2 - - - -
500 - 1700 nm InGaAs - - - DET10N2 -
750 - 1650 nm InGaAs - - - - PDA8GS
800 - 1700 nm InGaAs FGA015 - - - PDA015C(/M)
InGaAs FGA21
- SM05PD5A DET20C2 PDA20C2
InGaAs FGA01 b
- - DET01CFC(/M) -
InGaAs FDGA05 b - - - PDA05CF2
InGaAs - - - DET08CFC(/M)
800 - 1800 nm Ge FDG03
- SM05PD6A DET30B2 PDA30B2
Ge FDG50 - - DET50B2 PDA50B2
Ge FDG05 - - - -
900 - 1700 nm InGaAs FGA10 - SM05PD4A DET10C2 PDA10CS2
900 - 2600 nm InGaAs FD05D - - DET05D2 -
FD10D - - DET10D2 PDA10D2
950 - 1650 nm InGaAs - - - - FPD310-FC-NIR
1.0 - 2.9 µm PbS - FDPS3X3 - - -
1.0 - 5.8 µm InAsSb - - - - PDA10PT(-EC)
1.5 - 4.8 µm PbSe - FDPSE2X2 - - PDA20H(-EC)
2.0 - 5.4 µm HgCdTe (MCT) - - - - PDA10JT(-EC)
2.0 - 8.0 µm HgCdTe (MCT) VML8T0
VML8T4 d
- - - PDAVJ8
2.0 - 10.6 µm HgCdTe (MCT) VML10T0
VML10T4 d
- - - PDAVJ10
2.7 - 5.0 µm HgCdTe (MCT) VL5T0 - - - PDAVJ5
2.7 - 5.3 µm InAsSb - - - - PDA07P2
  • Calibrated Unmounted Photodiode
  • Unmounted TO-46 Can Photodiode
  • Unmounted TO-46 Can Photodiode with FC/PC Bulkhead
  • Photovoltaic Detector with Thermoelectric Cooler

Amplified PbSe Photodetector: 1.5 - 4.8 µm

PDA20H Photosensitivity
Click to Enlarge

Click Here for Raw Data
The graph above is for a 50 Ohm load.
Limited Stock Icon

These items will be retired without replacement when stock is depleted. If you require these parts for line production, please contact our OEM Team.

Item # PDA20Ha
Click Image to Enlargeb PDA20H
Detector Element
(Click for Image)
Wavelength Range 1.5 - 4.8 µm
Peak Wavelength (λP) 4.0 µm
Peak Responsivity 1.5 x 103 V/W (Min) at λP
3.0 x 103 V/W (Typ.) at λP
Photosensitivity Curve
(Click to View)
More Info
Active Area 4 mm2
(2 mm x 2 mm)
Gain 100X for Hi-Z Loads
50X for 50 Ω Loads
Bandwidth Range 0.2 Hz - 10 kHz
Noise-Equivalent Power (NEP)c 1.5x10-10 W/Hz1/2
  • All values in the table are for a 50 Ω load, unless otherwise specified.
  • All photodetectors are shown with the included SM1T1 Internal SM1 Adapter attached.
  • NEP measurement parameters: 300 K blackbody source, 600 Hz chopping frequency, 635 Hz bandpass filter with 70 Hz noise bandwidth and 22 °C ambient temperature.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
PDA20H Support Documentation
PDA20HPbSe Fixed Gain Detector, 1.5-4.8 µm, AC-Coupled Amplifier, 10 kHz BW, 4 mm2, 8-32 Taps
+1 Qty Docs Part Number - Metric Price Available
PDA20H-EC Support Documentation
PDA20H-ECPbSe Fixed Gain Detector, 1.5-4.8 µm, AC-Coupled Amplifier, 10 kHz BW, 4 mm2, M4 Taps

PDA Power Supply Cable

Pinout for Cable

The PDA-C-72 power cord is offered for the PDA line of amplified photodetectors when using with a power supply other than the one included with the detector. The cord has tinned leads on one end and a PDA-compatible 3-pin connector on the other end. It can be used to power the PDA series of amplified photodetectors with any power supply that provides a DC voltage. The pin descriptions are shown to the right.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
PDA-C-72 Support Documentation
PDA-C-7272" PDA Power Supply Cable, 3-Pin Connector

±12 VDC Regulated Linear Power Supply

  • Replacement Power Supply for the PDA and PDF Amplified Photodetectors Sold Above
  • ±12 VDC Power Output
  • Current Limit Enabling Short Circuit and Overload Protection
  • On/Off Switch with LED Indicator
  • Switchable AC Input Voltage (100, 120, or 230 VAC)
  • 2 m (6.6 ft) Cable with LUMBERG RSMV3 Male Connector
  • UL and CE Compliant

The LDS12B ±12 VDC Regulated Linear Power Supply is intended as a replacement for the supply that comes with our PDA and PDF line of amplified photodetectors sold on this page. The cord has three pins: one for ground, one for +12 V, and one for -12 V (see diagram above). A region-specific power cord is shipped with the LDS12B power supply based on your location. This power supply can also be used with the PDB series of balanced photodetectorsPMM series of photomultiplier modules,APD series of avalanche photodetectors, and the FSAC autocorrelator for femtosecond lasers.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
LDS12B Support Documentation
LDS12B±12 VDC Regulated Linear Power Supply, 6 W, 100/120/230 VAC

Internally SM1-Threaded Fiber Adapters

These internally SM1-threaded (1.035"-40) adapters mate terminated fiber to any of our externally SM1-threaded components, including our photodiode power sensors, our thermal power sensors, and our photodetectors. These adapters are compatible with the housing of the photodetectors on this page.

The APC adapter has two dimples in the front surface that allow it to be tightened with the SPW909 or SPW801 spanner wrench. The dimples do not go all the way through the disk so that the adapter can be used in light-tight applications when paired with SM1 lens tubes.

Item # S120-APCa S120-SMA S120-ST S120-SC S120-LC
Adapter Image
(Click the Image
to Enlarge)
S120-APC S120-SMA S120-ST S120-SC S120-LC
Fiber Connector Type FC/APCb SMA ST/PC SC/PCc LC/PC
Thread Internal SM1 (1.035"-40)
  • The S120-APC is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
  • This connector uses a wide key (2.2 mm).
  • In certain angle-independent applications, this adapter may also be used with SC/APC connectors.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
S120-APC Support Documentation
S120-APCCustomer Inspired! FC/APC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads
S120-SMA Support Documentation
S120-SMASMA Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads
S120-ST Support Documentation
S120-STST/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads
S120-SC Support Documentation
S120-SCSC/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads
S120-LC Support Documentation
S120-LCLC/PC Fiber Adapter Cap with Internal SM1 (1.035"-40) Threads

Externally SM1-Threaded Fiber Adapters

Each disk has four dimples, two in the front surface and two in the back surface, that allow it to be tightened from either side with the SPW909 or SPW801 spanner wrench. The dimples do not go all the way through the disk so that the adapters can be used in light-tight applications when paired with SM1 lens tubes. Once the adapter is at the desired position, use an SM1RR retaining ring to secure it in place.

Adapter Image
(Click the Image to Enlarge)
Threading External SM1 (1.035"-40)
  • The SM1FCA is designed with a 4° mechanical angle to compensate for the refraction angle of the output beam.
  • This connector uses a wide key (2.2 mm).
  • In certain angle-independent applications, this adapter may also be used with SC/APC connectors.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
SM1FC Support Documentation
SM1FCFC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads
SM1FCA Support Documentation
SM1FCAFC/APC Fiber Adapter Plate with External SM1 (1.035"-40) Threads
SM1SMA Support Documentation
SM1SMASMA Fiber Adapter Plate with External SM1 (1.035"-40) Threads
SM1ST Support Documentation
SM1STST/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads
SM1SC1 Support Documentation
SM1SC1SC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads
SM1LC Support Documentation
SM1LCLC/PC Fiber Adapter Plate with External SM1 (1.035"-40) Threads
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