Fiber-Coupled, Benchtop Tunable Laser Sources

  • General Purpose Telecom Tunable Lasers for C-Band or L-Band
  • +13 dBm Laser, 10 kHz Linewidth, Low Noise
  • Built-In Variable Optical Attenuator for Power Control
  • Dither Function Stabilizes Wavelength


Tunable Laser Source,

Touchscreen Interface

Related Items

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Block Diagram for TLX Tunable Lasers
Click to Enlarge

Block Diagram of the TLX Series Tunable Lasers. See the Operation tab for details.
*Monitor 1 is for internal use within the laser's control loop only.

Janis Valdmanis, Ph.D. Optics
Ultrafast Optoelectronics
General Manager

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  • Telecom Lasers Tunable on ITU 50 GHz Frequency Grid
    • TLX1: 1528 - 1566 nm (C-Band)
    • TLX2: 1570 - 1609 nm (L-Band)
  • Narrow 10 kHz Linewidth
  • +13 dBm Output Power and Low Noise Operation
  • Built-In Variable Optical Attenuator (VOA) for Automatic or Manual Power Control
  • Frequency Offset Option for Fine Tuning by ±30 GHz in 1 MHz Increments
  • Frequency Dither Option Aids in Wavelength Stabilization
  • Temperature-Controlled External Cavity Laser with Isolator
  • Full PM Fiber Optical Path
  • Control via Intuitive Touchscreen Interface or Remotely Using USB or RS-232 Connections

These Tunable Laser Sources emit light that can be tuned over commonly used telecommunication wavelength ranges. They are used in the research and design of wavelength division multiplexers (WDMs) and related components, during manufacturing testing, and in the implementation of full optical links. The TLX1 emits in the C-band, while the TLX2 emits in the L-band. The optical output has a narrow typical linewidth of 10 kHz, and operation with the frequency dither option stabilizes the laser wavelength. The wavelength tuning resolution is 50 GHz; these lasers also have a fine tuning frequency offset feature, allowing offset from -30.000 GHz to +30.000 GHz in increments of 1 MHz. Complete control over the optical output power is provided by the built-in variable optical attenuator, which can operate in Constant Attenuation or Constant Power modes. For complete specifications, see the Specs tab. 

The optical fiber path from the internal laser module through the optical output port is fully polarization maintaining (PM), and all external optical connections are made using FC/PC connectors. As shown in the above diagram, emission from the internal laser is coupled to the Laser Out port. The user has the option to couple this emission to the VOA In port via the supplied PM loop-back cable, or the user may alternatively couple an external laser to the VOA. Laser light input to the VOA In port should have a maximum input power of 20 dBm (100 mW), and the light should be linearly polarized along the slow axis (aligned to the connector key). See the Front & Back Panels tab for details on the input and output ports.

These laser sources can be controlled in two ways. The simplest method is using the intuitive touchscreen interface, which gives the user complete control over all instrument functionality. These instruments can also be operated remotely via the RS-232 or USB ports on the back panel. The Operation tab describes graphical user interface (GUI) and user-customizable features, and we provide a remote control user guide and a remote control software tool (see the Software tab) for download.  

Power and Environmental Specifications
Parameter Min Max
Main AC Voltage 100 VAC 250 VAC
Power Consumption - 60 VA
Line Frequency 50 Hz 60 Hz
Operating Temperature 10 °C 40 °C
Storage Temperature 0 °C 50 °C
Humiditya 5% Relative Humidity 85% Relative Humidity
  • Non-Condensing Environment
C-Band Laser Noise Spectrum
Click to Enlarge

FM Noise Spectrum of the tunable laser. The dither function helps stabilize the wavelength. Turning the dither off provides lower noise.
Laser Tuning
Item # TLX1 TLX2
Tunable Wavelength Range 1528 - 1566 nm 1570 - 1609 nm
Tunable Frequency Range 191.50 - 196.25 THz 186.35 - 190.95 THz
Laser Specifications
Parameter Unit Min Typ. Max
Optical Output Powera dBm 12.5 13.5 14.5
Frequency Accuracy GHz -1.5 - 1.5
Tuning Resolution GHz - 50 -
Fine Tuning Resolution MHz 1
Tuning Speed (Between Wavelengths) s - 10 -
Fine Tuning Range GHz -30 - 30
Side Mode Suppression Ratio dB 40 55 -
Optical Signal Noise Ratio dB 40 60 -
Intrinsic Linewidth kHz - 10 15
Relative Intensity Noise dB/Hz - - -145
Back Reflection dB - - -14
Polarization Extinction Ratio dB 18 - -
  • At the VOA Out Bulkhead
VOA Specifications
Optical Input Power 20 dBm (Max)a
External Laser Wavelength Range 1525 nm - 1610 nm
Optical Insertion Lossb 0.7 dB (Typ.)
Power Monitors Accuracyc ±0.5 dBm
Power Monitors Resolution 0.01 dBm
VOA Response Time 1 s (Typ.)
  • 22 dBm Absolute Max
  • VOA In to VOA Out
  • At 1550 nm
Housing Specifications
Outer Dimensions (W x D x H)a 250.0 mm x 300.0 mm x 122.0 mm
(9.84" x 11.81" x 4.80")
Internal Fiber PM PANDA-Style Fiber
Input/Output Port Fiber Connectors FC/PCb
  • For detailed dimensions, see the mechanical drawing by clicking on the red Docs icon () below.
  • See the Front & Back Panels tab for more details on the input and output ports.

Internal Setup

The block diagram below provides a basic illustration of the internal setup of the tunable lasers. The internal laser is routed via the loop-back cable on the front panel and input to the variable optical attenuator (VOA). Alternatively, the user can connect an external laser to the VOA input port. After the laser passes through the VOA, it exits through the optical output port on the front panel. The rear panel features ports for several additional monitor and control functions.

Block Diagram of TLX Series Tunable Lasers
Block Diagram of the Internal Setup of the Tunable Lasers.
*Monitor 1 is for internal use within the laser's control loop only.
Home Screen of the TLX1 and TLX2
Click to Enlarge

Main Menu (Home Screen) of the TLX1 and TLX2

Touchscreen Interface

These devices can be fully controlled by using the resistive touchscreen display for all functions. Either a finger or plastic stylus can be used to make selections on the screen. Additionally, the knob on the front panel of the housing can be used in place of the on-screen arrow buttons for quickly changing set-point values. Pressing (clicking) the knob will confirm a new set-point value.

The home screen is organized in three main sections.

  • Left Column: Buttons to turn each instrument function on or off.
  • Middle Column: Reports the current operating parameters of each instrument function. Tap in this column to go to the Settings page for each function.
  • Right Column: Buttons that provide access to various utility and help functions (e.g., control of audio and visual features).

The basic layout can be seen in the screenshots to the right.

Laser Settings Screen of the TLX1 and TLX2
Click to Enlarge

Laser Settings Screen

Laser Settings
From this screen, the user can tune the laser's output wavelength (see the Specs tab for the frequency and wavelength ranges of each device); these lasers also support a fine tuning frequency offset feature, allowing the frequency to be adjusted by an offset from -30.000 GHz to +30.000 GHz in increments of 1 MHz. The laser settings page also allows the user to set the dither function to aid in stabilizing the wavelength. Turning the dither off will result in lower phase and intensity noise; however, the wavelength may drift slightly over time.The noise performance of the laser with and without dither can be seen on the Specs tab. The laser settings screen also provides a readout of many of the laser operating parameters.

VOA Settings Screen of the TLX1 and TLX2
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VOA Settings Screen

VOA Settings
On this screen, the user can control the optical output power via the Variable Optical Attenuator (VOA). The VOA can be operated in one of two modes: Constant Attenuation or Constant Output Power. In Constant Attenuation mode, the attenuation level between the output of the laser and the output of the VOA remains fixed, allowing power changes at the input to be transferred to the output. In Constant Output Power Mode, the final optical output power is held constant independent of the input fluctuations. In this mode, the VOA is effectively used as a power stabilizer.

Rear Panel

The rear panel provides additional utility functions such as the laser safety interlock and the power monitor output, RS-232, and USB ports. Both the USB and RS-232 interfaces can be used for remote control operation of the tunable laser source. The serial commands and control features available are fully described in the Remote Control User Guide. The USB interface is also used for installing firmware upgrades as they become available.

All units are shipped from Thorlabs with a shorting device that is already installed in the interlock connector thus allowing the instrument to be operated normally right out of the box. To make use of the interlock feature, a 2.5 mm plug can be wired to the remote interlock switch and plugged into the back-panel interlock jack in place of the shorting plug. The electrical specifications for that function can be found in the manual (PDF link).

Front Panel

Front Panel of the TLX1 and TLX2
Click to Enlarge

TLX1 Front Panel
Callout Description
1 Touchscreen Display and Control
2 Value Adjustment Knob
3 Key Switch and Indicator Light for Internal Laser
4a Laser Output,
Accepts PM Fiber with FC/PC Connector
5a VOA Input (External Laser Input),
Accepts PM Fiber with FC/PC Connector
6a VOA Output,
Accepts PM Fiber with FC/PC Connector
7 On/Standby Button
  • Uses PM PANDA Fiber for Internal Connection

Back Panel

Back Panel of the TLX1 and TLX2
Click to Enlarge

TLX1 Back Panel
Callout Description
1a I/O Control Port
Outputs from Two Integrated Power Monitors
2 Laser Interlock Jack
3a RS-232 Control Port
4 USB Port (Type B)
5 AC Power Cord Connector
6 Fuse Tray
7 AC Power Switch
  • See the Pin Diagrams tab for pin assignments.

I/O DB15 Connector (Female)

The I/O connector provides analog outputs from the two power monitors.

Pin Description Pin Description
1 Reserved for Future Use 9 Analog Ground
2 Power Monitor 2 10 Analog Ground
3 Power Monitor 3 11 Reserved for Future Use
4 Reserved for Future Use 12 Reserved for Future Use
5 Analog Ground 13 Reserved for Future Use
6 Analog Ground 14 Monitor 2 Gain Indicator
7 Analog Ground 15 Monitor 3 Gain Indicator
8 Analog Ground - -

RS-232 Connector (Male)

The RS-232 connector is provided to support remote operation.

Pin Description
1 Not Connected
2 RS-232 Input
3 RS-232 Output
4 Not Connected
5 Digital Ground
6 Not Connected
7 Not Connected
8 Not Connected
9 Not Connected

USB, Type B (Female)

The USB connector is provided for firmware upgrades and will support remote operation in the future.

Each Tunable Laser Source includes:

  • Laser Source Main Unit
  • Power Cord According to Local Supply (Determined by Ordering Location)
  • PM Loop-Back Fiber Optic Cable
  • Interlock Keys for Front Panel
  • 2.5 mm Interlock Pin (Pre-installed in Back Panel)
  • 1.25 A, 250 VAC Fuse
  • USB Type A to Type B Cable, 6' Long
Screen Capture of the Remote Control Tool Software
Click to Enlarge

The GUI of the Remote Control Software Tool

Software for the TLX1 and TLX2 Tunable Laser Sources

Control the Laser Sources Remotely via Serial Commands
Serial commands sent to the TLX1 or TLX2 can control the functionality of internal laser module and variable optical attenuator (VOA), as well as set general system parameters. The commands can be sent from a computer running any operating system to the RS-232 port on the back panel of the TLX series laser. Computers running Windows® 7, or later versions of the operating system, can send serial commands to the USB port on the back panel of the TLX series laser. The touchscreen interface remains active while the laser is controlled remotely. Descriptions of how to connect a controlling computer to the TLX series laser, the serial command set, and descriptions of each command are included in the Remote Control User Guide.

Application Demonstrating GUI-Based Remote Control of the Laser Sources
The Remote Control Software Tool, which is available for download, is an example graphical user interface (GUI) provided for testing, demonstrating, and exploring the use of the different serial commands. This program is not required to operate the laser source remotely. It opens a connection to the laser source and sends commands in response to buttons clicked by users. Commands sent to the TLX series laser, responses from it, and status information messages are logged to the three rectangular fields located beneath the buttons. Please see the Remote Control User Guide for more information. This program can be used as a basis for the development of custom applications. Please contact us to request the source code.


Version 1.8.7 (May 5, 2022)

Click on the link below to download the Remote Control Software Tool.

Software Download

Firmware Update

Version 1.8.3 (January 13, 2020)

Click on the link below to download the latest firmware.

Firmware Download

Laser Safety and Classification

Safe practices and proper usage of safety equipment should be taken into consideration when operating lasers. The eye is susceptible to injury, even from very low levels of laser light. Thorlabs offers a range of laser safety accessories that can be used to reduce the risk of accidents or injuries. Laser emission in the visible and near infrared spectral ranges has the greatest potential for retinal injury, as the cornea and lens are transparent to those wavelengths, and the lens can focus the laser energy onto the retina. 

Laser Glasses Laser Curtains Blackout Materials
Enclosure Systems Laser Viewing Cards Alignment Tools
Shutter and Controllers Laser Safety Signs

Safe Practices and Light Safety Accessories

  • Laser safety eyewear must be worn whenever working with Class 3 or 4 lasers.
  • Regardless of laser class, Thorlabs recommends the use of laser safety eyewear whenever working with laser beams with non-negligible powers, since metallic tools such as screwdrivers can accidentally redirect a beam.
  • Laser goggles designed for specific wavelengths should be clearly available near laser setups to protect the wearer from unintentional laser reflections.
  • Goggles are marked with the wavelength range over which protection is afforded and the minimum optical density within that range.
  • Laser Safety Curtains and Laser Safety Fabric shield other parts of the lab from high energy lasers.
  • Blackout Materials can prevent direct or reflected light from leaving the experimental setup area.
  • Thorlabs' Enclosure Systems can be used to contain optical setups to isolate or minimize laser hazards.
  • A fiber-pigtailed laser should always be turned off before connecting it to or disconnecting it from another fiber, especially when the laser is at power levels above 10 mW.
  • All beams should be terminated at the edge of the table, and laboratory doors should be closed whenever a laser is in use.
  • Do not place laser beams at eye level.
  • Carry out experiments on an optical table such that all laser beams travel horizontally.
  • Remove unnecessary reflective items such as reflective jewelry (e.g., rings, watches, etc.) while working near the beam path.
  • Be aware that lenses and other optical devices may reflect a portion of the incident beam from the front or rear surface.
  • Operate a laser at the minimum power necessary for any operation.
  • If possible, reduce the output power of a laser during alignment procedures.
  • Use beam shutters and filters to reduce the beam power.
  • Post appropriate warning signs or labels near laser setups or rooms.
  • Use a laser sign with a lightbox if operating Class 3R or 4 lasers (i.e., lasers requiring the use of a safety interlock).
  • Do not use Laser Viewing Cards in place of a proper Beam Trap.


Laser Classification

Lasers are categorized into different classes according to their ability to cause eye and other damage. The International Electrotechnical Commission (IEC) is a global organization that prepares and publishes international standards for all electrical, electronic, and related technologies. The IEC document 60825-1 outlines the safety of laser products. A description of each class of laser is given below:

Class Description Warning Label
1 This class of laser is safe under all conditions of normal use, including use with optical instruments for intrabeam viewing. Lasers in this class do not emit radiation at levels that may cause injury during normal operation, and therefore the maximum permissible exposure (MPE) cannot be exceeded. Class 1 lasers can also include enclosed, high-power lasers where exposure to the radiation is not possible without opening or shutting down the laser.  Class 1
1M Class 1M lasers are safe except when used in conjunction with optical components such as telescopes and microscopes. Lasers belonging to this class emit large-diameter or divergent beams, and the MPE cannot normally be exceeded unless focusing or imaging optics are used to narrow the beam. However, if the beam is refocused, the hazard may be increased and the class may be changed accordingly.  Class 1M
2 Class 2 lasers, which are limited to 1 mW of visible continuous-wave radiation, are safe because the blink reflex will limit the exposure in the eye to 0.25 seconds. This category only applies to visible radiation (400 - 700 nm).  Class 2
2M Because of the blink reflex, this class of laser is classified as safe as long as the beam is not viewed through optical instruments. This laser class also applies to larger-diameter or diverging laser beams.  Class 2M
3R Class 3R lasers produce visible and invisible light that is hazardous under direct and specular-reflection viewing conditions. Eye injuries may occur if you directly view the beam, especially when using optical instruments. Lasers in this class are considered safe as long as they are handled with restricted beam viewing. The MPE can be exceeded with this class of laser; however, this presents a low risk level to injury. Visible, continuous-wave lasers in this class are limited to 5 mW of output power.  Class 3R
3B Class 3B lasers are hazardous to the eye if exposed directly. Diffuse reflections are usually not harmful, but may be when using higher-power Class 3B lasers. Safe handling of devices in this class includes wearing protective eyewear where direct viewing of the laser beam may occur. Lasers of this class must be equipped with a key switch and a safety interlock; moreover, laser safety signs should be used, such that the laser cannot be used without the safety light turning on. Laser products with power output near the upper range of Class 3B may also cause skin burns.  Class 3B
4 This class of laser may cause damage to the skin, and also to the eye, even from the viewing of diffuse reflections. These hazards may also apply to indirect or non-specular reflections of the beam, even from apparently matte surfaces. Great care must be taken when handling these lasers. They also represent a fire risk, because they may ignite combustible material. Class 4 lasers must be equipped with a key switch and a safety interlock.  Class 4
All class 2 lasers (and higher) must display, in addition to the corresponding sign above, this triangular warning sign.  Warning Symbol

Janis Valdmanis, Ph.D. Optics
Ultrafast Optoelectronics
General Manager

Custom and OEM Options

When your application requirements are not met by our range of catalog products or their variety of user-configurable features, please contact me to discuss how we may serve your custom or OEM needs.  

Request a Demo Unit

Explore the benefits of using a Thorlabs high-speed instrument in your setup and under your test conditions with a demo unit. Contact me for details.

Contact Me

MX40B with cover removed
Click to Enlarge

The MX40B Digital Reference Transmitter

Design, Manufacturing, and Testing Capabilities

Thorlabs' Ultrafast Optoelectronics Team designs, develops, and manufactures high-speed components and instrumentation for a variety of photonics applications having frequency responses up to 110 GHz. Our extensive experience in high-speed photonics is supported by core expertise in RF/microwave design, optics, fiber optics, optomechanical design, and mixed-signal electronics. As a division of Thorlabs, a company with deep vertical integration and a portfolio of over 20,000 products, we are able to provide and support a wide selection of equipment and continually expand our offerings.

Our catalog and custom products include a range of integrated fiber-optic transmitters, modulator drivers and controllers, detectors, receivers, pulsed lasers, variable optical attenuators, and a variety of accessories. Beyond these products, we welcome opportunities to design and produce custom and OEM products that fall within our range of capabilities and expertise. Some of our key capabilities are:

  • Detector and Receiver Design, to 70 GHz
  • Fiber-Optic Transmitter Design, to 110 GHz
  • RF & Microwave Design and Simulation
  • Design of Fiber-Optic and Photonics Sub-Assemblies
  • High-Speed Testing, to 110 GHz
  • Micro-Assembly and Wire Bonding
  • Hermetic Sealing of Microwave Modules
  • Fiber Splicing of Assemblies
  • Custom Laser Engraving
  • Qualification Testing

Overview of Custom and Catalog Products

Our catalog product line includes a range of integrated fiber-optic transmitters, modulator drivers and controllers, detectors, pulsed lasers, and accessories. In addition to these, we offer related items, such as receivers and customized catalog products. The following sections give an overview of our spectrum of custom and catalog products, from fully integrated instruments to component-level modules.

Fiber-Optic Instruments

To meet a range of requirements, our fiber-optic instruments span a variety integration levels. Each complete transmitter includes a tunable laser, a modulator with driver amplifier and bias controller, full control of optical output power, and an intuitive touchscreen interface. The tunable lasers, modulator drivers, and modulator bias controllers are also available separately. These instruments have full remote control capability and can be addressed using serial commands sent from a PC.

  • Fiber-Optic Transmitters, to 110 GHz
  • Linear and Digital Transmitters
  • Electrical-to-Optical Converters, to 110 GHz
  • Modulator Drivers
  • Modulator Bias Controllers
  • C- and L-Band Tunable Lasers

Customization options include internal laser sources, operating wavelength ranges, optical fiber types, and amplifier types.

Fiber-Optic Components

Our component-level, custom and catalog fiber-optic products take advantage of our module design and hermetic sealing capability. Products include detectors with frequency responses up to 50 GHz, and we also specialize in developing fiber-optic receivers, operating up to and beyond 40 GHz, for instrumentation markets. Closely related products include our amplifier modules, which we offer upon request, variable optical attenuators, microwave cables, and cable accessories.

  • Hermetically-Sealed Detectors, to 50 GHz
  • Fiber-Optic Receivers, to 40 GHz
  • Amplifier Modules
  • Electronic Variable Optical Attenuators
  • Microwave Cables and Accessories

Customization options include single mode and multimode optical fiber options, where applicable, and detectors optimized for time or frequency domain operation.

Free-Space Instruments

Our free-space instruments include detectors with frequency responses around 1 GHz and pulsed lasers. Our pulsed lasers generate variable-width, nanosecond-duration pulses, and a range of models with different wavelengths and optical output powers are offered. User-adjustable repetition rates and trigger in/out signals provide additional flexibility, and electronic delay-line products enable experimental synchronization of multiple lasers. We can also adapt our pulsed laser catalog offerings to provide gain-switching capability for the generation of pulses in the 100 ps range.

  • Pulsed Lasers with Fixed 10 ns Pulse Duration
  • Pulsed Lasers with Variable Pulse Width and Repetition Rates
  • Electronic Delay Units to Synchronize NPL Series Pulsed Lasers
  • Amplified Detectors

Customization options for the pulsed lasers include emission wavelength, optical output powers, and sub-nanosecond pulse widths.

Choose Optical Transmitter by Application

  1. Beginning at the left side of the table, choose your desired system characteristics.
  2. Follow the table to the right and continue to select characteristics from the options within the same row as your previous selection.
  3. After reaching a Base Item #, choose a laser type. Your system's item # will be your base item # combined with the suffix for your laser type, e.g. MX40B-1310.
Start Here Follow the Table to the Right and Choose From These Options Find Your System Here
Modulator Type Primary Application Modulation Format Speed RF Input Base Item # Item # Suffix:
Laser Type
Amplitude Time Domain / Eye Diagram Linear / 4-Level PAM4 32 GBaud Differential MX35D No Suffix:
C-Band Tunable Laser

L-Band Tunable Laser

1310 nm Fixed Laser

850 nm Fixed Lasera,b
Single Ended MX35E
56 GBaud MX65E
Digital / 2-Level NRZ / OOK 10 Gbps MX10B
40 Gbps MX40B
56 Gbps MX50E
56 Gbps MX65E
Frequency Domain / VNA 40 GHz MX40G
70 GHz MX70G
110 GHz MX110G
Phase 10 Gbps MX10C
40 Gbps MX40C
  • The 850 nm fixed laser is not available for the following base item #s:
    • MX10C
    • MX40C
    • MX65E
    • MX70G
    • MX110G
  • The MX40G-850 transmitter is available through the website. For other systems with an 850 nm fixed laser, excluding those listed in footnote a, please contact Tech Support.

Choose Optical Transmitter Instrument by Features

Transmitter Instruments and Tunable Lasers
Item # Speed Internal Laser Internal Modulator
RF Amplifier
Variable Optical
Attenuator (VOA)
Automatic Bias Controller
(770 - 980 nm)
N/A - - - yes yes
(1250 - 1610 nm)
N/A - - - yes yes
Tunable Telecom-Grade Laser Sources
TLX1 N/A C-Band, Tunable - - - yes
TLX2 N/A L-Band, Tunable
High-Speed Modulator Drivers
(1250 - 1610 nm)
12.5 Gb/sa - - Digital yes yes
(1250 - 1610 nm)
40 Gb/sa
High-Speed Optical Transmitters
MX10B 12.5 Gb/sa C-Band, Tunable Intensity Digital yes yes
MX10B-LB 12.5 Gb/sa L-Band, Tunable
MX10B-1310 12.5 Gb/sa 1310 nm, Fixed
MX10C 12.5 Gb/sa C-Band, Tunable Phase Digital - yes
MX10C-LB 12.5 Gb/sa L-Band, Tunable
MX10C-1310 12.5 Gb/sa 1310 nm, Fixed
MX35E 35 GHzb C-Band, Tunable Intensity Linear yes yes
MX35E-LB 35 GHzb L-Band, Tunable
MX35E-1310 35 GHzb 1310 nm, Fixed
MX35D 35 GHzb C-Band, Tunable Intensity Linear with
yes yes
MX35D-LB 35 GHzb L-Band, Tunable
MX35D-1310 35 GHzb 1310 nm, Fixed
MX40B 40 Gb/sa C-Band, Tunable Intensity Digital yes yes info
MX40B-LB 40 Gb/sa L-Band, Tunable
MX40B-1310 40 Gb/sa 1310 nm, Fixed
MX40C 40 Gb/sa C-Band, Tunable Phase Digital - yes
MX40C-LB 40 Gb/sa L-Band, Tunable
MX40C-1310 40 Gb/sa 1310 nm, Fixed
MX50E-850 50 GHzb 852 nm, Fixed Intensity Linear yes yes
MX65E 65 GHzb C-Band, Tunable Intensity Linear yes yes
MX65E-LB 65 GHzb L-Band, Tunable
MX65E-1310 65 GHzb 1310 nm, Fixed
E-O Converters for VNA Applications
MX40G 40 GHzb C-Band, Tunable Intensity - yes yes
MX40G-LB 40 GHzb L-Band, Tunable
MX40G-850 40 GHzb 850 nm, Fixed
MX40G-1310 40 GHzb 1310 nm, Fixed
MX70G 70 GHzb C-Band, Tunable Intensity - yes yes
MX70G-LB 70 GHzb L-Band, Tunable
MX70G-1310 70 GHzb 1310 nm, Fixed
MX70G-DB1 70 GHzb C-Band, Tunable Intensity - yes yes
1310 nm, Fixed
MX110G 110 GHzb C-Band, Tunable Intensity - yes yes
MX110G-1310 110 GHzb 1310 nm, Fixed
  • Maximum Supported Digital Bit Rate
  • Maximum Analog Bandwidth

The capabilities of Thorlabs' extensive range of transmitter instruments are summarized in the text and table below. All members of this product series share a similar interface, as well as a common remote control command set.

Automatic Bias Controller
Thorlabs' fully-featured automatic bias controller provides complete and precise control of DC bias and optical output power for any fiber-coupled LiNbO3 EO intensity modulator, regardless of signal speed. Automatic bias controllers are ideal for use within a customized setup that uses an external laser, intensity modulator, signal source, and RF amplifier.

Tunable Telecom-Grade Laser Sources
Emitting in the C-band or the L-band, these lasers have narrow typical linewidths of 10 kHz. A frequency dither option aids in stabilizing the laser wavelength, and the integrated variable optical attenuator (VOA) provides optical output power control. These lasers are tunable in 50 GHz steps across the ITU frequency grid, and feature a 1 MHz step size fine-tune capability, as well.

High-Speed Modulator Drivers
With an operational wavelength range of 1250 nm to 1610 nm, each modulator driver provides control for an external fiber-coupled LiNbO3 EO modulator. Each modulator driver includes an RF amplifier with amplitude and eye-crossing controls and accepts an external drive signal source. Models with integrated automatic bias controllers are offered for use with intensity EO modulators.

High-Speed Optical Transmitters
Designed to provide fully-integrated solutions for high-speed light modulation, these systems are built around a LiNbO3 intensity or phase modulator. The MX10B, MX40B, MX10C, and MX40C series of systems include a digital (limiting) RF amplifier, which offers fixed gain and an adjustable output voltage swing. The MX35E, MX50E, and MX65E series include a high-bandwidth linear (analog) RF amplifier, making it well suited for pulse amplitude modulation and related applications.

E-O Converters for VNA Applications
With our MX40G, MX70G, and MX110G series of E-O converters, any E-E vector network analyzer can be used to perform optical testing up to 40 GHz, 70 GHz, and 110 GHz respectively. The E-O converter is a fully-integrated solution that includes a laser, a modulator, and bias control.

Posted Comments:
user  (posted 2024-01-22 12:49:55.34)
I am interested in the L band tuneable laser. What is the typical power leaving the "Laser Out" socket, as a function of wavelength ? Thank you !
ksosnowski  (posted 2024-02-01 12:25:39.0)
Thanks for reaching out to Thorlabs. The output power is fairly flat with wavelength. There will be some variation unit-to-unit, both in the average power and the exact wavelength-dependence, but typically the power does not deviate by more than 0.2 dB or so. I have reached out directly to share some sample data from our devices.
subba rao y v  (posted 2022-10-24 17:49:07.517)
Dear Sir, I have few queries about TLX1 1) What is VOA attenuation range? 2) The stability or variation of the laser output wavelength with respect to temperature? 3) The stability or variation of the laser output wavelength with respect to continuous operation over a duration? 4)Whether the CW laser is aligned to slow axis with linear polarization? 5)Without dither, Can the tunable laser stabilize wavelength?
ksosnowski  (posted 2022-11-08 01:38:06.0)
Hello Subba, thanks for reaching out to Thorlabs. For TLX1, in the constant attenuation mode the user can choose a setpoint up to 20dB of attenuation. In the constant output power mode the VOA will go to higher attenuation if necessary to try to achieve the setpoint. The max possible attenuation in the constant output power mode is not specified and changes from unit to unit (approx. 25-40dB). We do not specify an exact wavelength stability however it is more stable with dither applied and with a stable ambient temperature. The linear polarization component is aligned with the slow axis of the fiber, and the laser can stabilize without dither, but has increased drift over longer periods. We do not expect dithering to change the instantaneous linewidth or coherence length. I have reached out directly to discuss these topics further.
Gaoce Han  (posted 2019-07-30 21:27:29.15)
Dear Ashley, I want to buy a tunable laser this week and the requirements for the laser are 1. Central wavelength: 1550 nm 2. Wavelength range: at least 1530~1570 nm, which means the tuning range is > 40 nm 3. Linewidth: narrow linewidth 4. Tuning speed: fast tuning Thus I am interested in the products TLX1. About it, I need to specifically know some important parameters so that I can make decision 1. Stability: if the tunable laser is working at a fixed frequency, what is the curve frequency versus time? (see fig.1) 2. Tuning step: if the tunable laser is idealy linearly tuning, which is not possible, what is the tuning principle of it? (see fig.2) 3. Tuning speed: what is the maximum tuning speed if the tuning range is 40 nm @ 1550 nm? In terms of fig.1 and fig.2, they are only examples, the actual curves could be different. What do I want to know have been explained in them. Please give me the curves or parameters as detailed as possible. I will make the final decision this week, could you please respond me ASAP? Many thanks! Best wishes, Gaoce
YLohia  (posted 2019-07-31 09:03:32.0)
Hello Gaoce, our Applications Engineers can be contacted directly via email ( We will reach out to you to discuss your application.
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Fiber-Coupled, Benchtop Tunable Laser Sources

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TLX1 Support Documentation
TLX1Benchtop Tunable Laser Source, C-Band
TLX2 Support Documentation
TLX2Benchtop Tunable Laser Source, L-Band