Solis^® High-Power LEDs for Microscopy

Features

• 20 Wavelengths Available (See the Table to the Right for Options)
• Fanless Design Efficiently Dissipates Heat without Introducing Vibrations
• Lightweight Package for Mounting Directly to Microscope Ports, Eliminating the Need for Liquid Light Guides (LLGs)
• Collimated LED Output through Large Ø48.3 mm (1.90") Clear Aperture
• Integrated Electronics Enable Smart Safety Features with Compatible Drivers
• Compatible with Port Adapters for Use with Olympus, Nikon, Leica, Zeiss, and Cerna^® Microscopes
  (Sold Separately Below)

Configure Your Solis^® LED System

• Solis LED Head
• LED Driver (Choose One, Sold Separately) 
  • DC20 Plug-and-Play Driver with External TTL Input
  • DC2200 Touchscreen Driver with Advanced Modulation Functions
• One Microscope Port Adapter (See Table Below for Compatibility Information)

Thorlabs' Solis LEDs for microscopy deliver several watts of total output power from a lightweight, vibration-free package. They provide high-power illumination that can be coupled directly to the epi-illumination path on a microscope. Light from the LED is collimated through a large Ø48.3 mm aperture that can be attached via an adapter (available separately below) to the epi-illumination paths of many industry-standard microscopes from Olympus, Nikon, Leica, and Zeiss as well as the six-cube epi-illumination path available on many of Thorlabs' Cerna Microscopes. To install, select one of Thorlabs' microscope port adapters (available separately below), screw it onto the end of the housing, and secure the LED to a compatible microscope. Each Solis LED includes a user-installable diffuser plate (Item # DG20-1500), which can be used to make the output profile of the LED more uniform, and can help to provide even illumination at the sample plane.

The lightweight design features passive cooling instead of an internal fan in order to eliminate vibrations that normally degrade image quality in a microscopy setup. Each LED is mounted to a heatsink inside of a 127.8 mm x 127.8 mm x 162.0 mm vented housing to efficiently dissipate heat. As an added level of protection, the integrated internal memory is programmed to trigger an automatic shutdown if the LED internal temperature reaches 95 °C, preventing damage from overheating. The LED will restart after it has cooled to a temperature below 95 °C. For more Solis LED performance information when using Solis LEDs, please see the Performance tab.

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Thorlabs offers two options for powering a Solis^® LED: the plug-and-play DC20 driver (left) and the touchscreen DC2200 driver (right).

Solis LED Drivers
We offer two driver options for our Solis LEDs. The DC20 Plug-and-Play Solis LED Driver (available separately below) features a knob that provides LED current control and functions as an LED On/Off switch as well as a BNC input for external TTL modulation signals.

The DC2200 Touchscreen LED Driver (available separately below) has an intuitive, touchscreen interface that supports both basic current control and more advanced modulation functions for the Solis LED head. For example, this driver allows the LED output power to be set at a fraction of the maximum desired brightness, and it control the LED drive current. For users that require modulation control, the driver integrates both internal and external modulation and pulsed modes. Internal modulation modes include settings for sine, square, and triangle waveforms as well as ways to generate rectangular pulse trains. External modulation modes allow this driver to accept an arbitrary waveform from a function generation or external TTL signals for syncing on/off states with other lab equipment.

Both drivers automatically read and set the current limit from the Solis LED's internal memory to protect against overdriven currents. A comparison of the two drivers is provided on the Solis LED Drivers tab.

Item #a	Info	Color (Click for Spectrumb)	Dominant Wavelengthc	Minimum Collimated Output Powerd	Typical Collimated Output Powerd	Max Current (CW)	Max Forward Voltage	Bandwidth (FWHM)	Emitter Size	Collimating Optics (Installed)	Typical Lifetime
SOLIS-365C		UV	365 nm	3.0 W	4.0 W	4500 mA	4.0 V	10 nm	2 mm x 2 mm	LB1723-A ACL25416U-A	>12 000 h
SOLIS-385C		UV	385 nm	4.0 W	5.1 W	4500 mA	4.0 V	12 nm	2 mm x 2 mm		>29 000 h
SOLIS-405C		UV	405 nm	5.0 W	3.9 W	4500 mA	4.0 V	12 nm	2 mm x 2 mm		>40 000 h
SOLIS-415C		Violet	415 nm	5.8 W	7.0 W	2000 mA	14.0 V	14 nm	3.5 mm x 3.5 mm		>10 000 h
SOLIS-445C		Royal Blue	445 nm	5.4 W	7.1 W	9000 mA	3.8 V	23 nm	Ø3 mm		>10 000 h
SOLIS-470C		Blue	470 nm	3.0 W	3.7 W	4000 mA	8.0 V	34 nm	2.8 mm x 2.8 mm		>10 000 h
SOLIS-505C		Cyan	505 nm	1.0 W	1.5 W	4000 mA	6.5 V	42 nm	2.8 mm x 2.8 mm		>10 000 h
SOLIS-525C		Green	525 nm	2.4 W	3.1 W	9000 mA	5.0 V	32 nm	Ø3 mm		>10 000 h
SOLIS-4C		Lime	565 nm	3.2 W	6.1 W	10 000 mA	4.3 V	100 nm	2.6 mm x 3.2 mm		>10 000 h
SOLIS-590C		Amber	590 nm	350 mW	570 mW	1000 mA	12.5 V	16.5 nm	3.2 mm x 3.2 mm		>10 000 h
SOLIS-595C		Amber	595 nm	700 mW	1.1 W	700 mA	14.0 V	77 nm	2.8 mm x 2.8 mm		>10 000 h
SOLIS-617C		Orange	617 nm	1.5 W	2.4 W	10 000 mA	4.0 V	17 nm	2.6 x 3.2 mm		>10 000 h
SOLIS-623C		Red	623 nm	3.8 W	4.8 W	9000 mA	4.8 V	17 nm	3 mm x 3 mm		>10 000 h
SOLIS-660C		Deep Red	660 nm	2.0 W	2.7 W	1000 mA	12.5 V	21 nm	3.2 mm x 3.2 mm		>10 000 h
SOLIS-740C		Red	740 nm	2.0 W	3.3 W	1500 mA	13.4 V	45 nm	3.2 mm x 3.2 mm	LB1723-B ACL25416U-B	>10 000 h
SOLIS-850C		IR	850 nm	2.7 W	3.6 W	1000 mA	13.8 V	39 nm	Ø6.5 mme		>40 000 h
SOLIS-940C		IR	940 nm	2.5 W	3.7 W	2000 mA	7.5 V	55 nm	3.2 mm x 3.2 mm		>10 000 h
SOLIS-1C		Cold White	N/Af	3.3 W	4.2 W	9000 mA	3.5 V	N/A	3 mm x 3 mm	LB1723-A ACL25416U-A	>10 000 h
SOLIS-2C		Warm White	N/Ag	3.2 W	4.0 W	1500 mA	12.5 V	N/A	5 mm x 5 mm		>100 000 h
SOLIS-3C		Day Light White	N/Ah	3.5 W	4.6 W	10 000 mA	3.5 V	N/A	Ø4.25 mm		>10 000 h

• LED specifications are nominal values.
• A file with the LED spectral data can be downloaded here.
• For LEDs in the visible spectrum, the dominant wavelength indicates the wavelength at which the LED appears brightest to the human eye. For UV and IR LEDs, the dominant wavelength corresponds to the peak wavelength. The dominant wavelength for visible LEDs may not correspond to the peak wavelength as measured by a spectrograph.
• Measured at the Max Current (CW). The LED output power can be decreased by lowering the current supplied to the LED.
• This LED is comprised of four emitters with a lens of the specified diameter.
• This LED has a correlated color temperature of 6500 K.
• This LED has a correlated color temperature of 3000 K.
• This LED has a correlated color temperature of 5700 K.

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A comparison of the typical collimated output for a Solis LED. The actual spectra will vary from LED to LED within specifications.

LED Output Power
The actual spectral output and total output power of any given LED will vary due to variations in the manufacturing process and operating parameters, such as temperature and current. Both a typical and minimum output power are specified to help you select an LED that suits your needs. Each Solis^® high-power LED will provide at least the minimum specified output power at the maximum current. In order to provide a point of comparison for the relative powers of LEDs with different nominal wavelengths, the spectra in the plot to the right have been scaled to the typical collimated output power for each LED. The intensities shown in this graph are representative, not absolute. An Excel file with normalized and scaled spectra for all of the mounted high-power LEDs can be downloaded here.

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Click Here for Raw Data
The output power remains stable over a 24-hour period. Small dips in the curve are due to slight variations in climate condition (±2 °C).

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Shown are the SOLIS-1C, SOLIS-2C, and SOLIS-3C LED spectra scaled to typical power. The region in blue indicates a drop in the spectral flux. The SOLIS-3C provides significantly more power for applications that require strong illumination at these wavelengths, such as excitation of GFPs.

Stability at Elevated Room Temperatures

The thermal dissipation performance of these Solis^® LEDs has been optimized for stable power output. The heat sink is directly mounted to the LED mount so as to provide optimal thermal contact, prolonging the life of the diode by keeping the junction temperature at the lowest possible minimum.

One characteristic of LEDs is that they naturally exhibit power degradation with time. Often this power degradation is slow, but there are also instances where large, rapid drops in power, or even complete LED failure, occur. LED lifetimes are defined as the time it takes a specified percentage of a type of LED to fall below some power level. The parameters for the lifetime measurement can be written using the notation B_XX/L_YY, where XX is the percentage of that type of LED that will provide less than YY percent of the specified output power after the lifetime has elapsed. Thorlabs defines the lifetime of our LEDs as B₅₀/L₅₀, meaning 50% of the LEDs with a given Item # will fall below 50% of the initial optical power at the end of the specified lifetime. For example, if a batch of 100 LEDs is rated for 4000 mW of output power, 50 of these LEDs can be expected to produce an output power of ≥2000 mW after the specified LED lifetime has elapsed.

Solis LEDs can be operated at room temperatures from 0 to 40 °C. An elevated room temperature can be useful if a sample and microscope needs to be maintained at such temperatures for experiments. The graph at the right shows measurements of the output power for a SOLIS-3C LED at 40 °C over a period of 24 hours; the output power remains stable after the initial warm-up period.

Increased Power for Light-Excited Fluorophores

The Solis LED light sources are designed for use in fluorescence microscopy, such as GFP or GFP-derived fluorescent protein imaging. Thorlabs offers LEDs for specific wavelengths as well as white LEDs that cover the entire visible light spectrum. SOLIS-1C, SOLIS-2C, and SOLIS-3C white LEDs provide high-power excitation light for many fluorophores. However, the output power is not the same at every wavelength, as seen in the graph to the right. Most LEDs exhibit a drop in output power from 470 nm to 520 nm. While most imaging applications are unaffected, other light-sensitive applications may require more power in this region.

With a constant output power from 450 nm to 650 nm, the SOLIS-3C LED offers significantly more power in this region compared to the SOLIS-1C and SOLIS-2C LEDs. To demonstrate this, we measured the irradiance of the SOLIS-1C and SOLIS-3C LEDs by placing a FB480-10 480 nm bandpass filter in front of an S120VC detector at a distance 200 mm on-axis from the LEDs. The irradiance of the SOLIS-1C and SOLIS-3C LEDs with the filter were 38 µW/mm² and 45 µW/mm², respectively. Thus, when compared to the SOLIS-1C, the SOLIS-3C is most beneficial when higher power is needed in this wavelength range. Note that these irradiance values are not representative of the irradiance across the whole spectrum, but rather from 470 nm to 490 nm.

Solis^® LED Pin Diagram

Male 12 Pin Neutrik MiniCON Connector

Do-It-Yourself Mounting Options

While the Solis^® LEDs are designed to mount easily to a microscope port, they can also be mounted to an optical table or breadboard. A 1/4"-20 (M6) tapped hole is provided at each corner on the back of the housing for custom mounting applications. The front aperture is internally SM2 threaded (2.035"-40), which provides compatibility with Thorlabs' SM2 Lens Tubes and 60 mm Cage Systems.

Below are two examples of how a Solis LED can be mounted to an optical table. The top photo shows a Solis LED mounted using a cage plate and Ø1" post. The bottom photo shows a Solis LED mounted using a Ø2" lens tube, lens tube slip rings, Ø1/2" posts, and Ø1/2" post holders. Please refer to the tables to the left for a list of components in each mounting setup.

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The SOLIS-1C shown mounted to an optical table using the SM2T2 adapter, a LCP01 60 mm cage plate, and a Ø1" post.

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The SOLIS-1C shown mounted to an optical table using an SM2L15 lens tube, two SM2RC lens tube mounts, two Ø1/2" posts, and one BA2 post holder base.

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Once locked into place, the LED requires no additional support.

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An exploded view of the Solis^® LED and its connection with the CSE2100 epi-illuminator module.

Using Solis^® in Cerna^® Microscope Systems

Solis^® LEDs, which can have either narrowband or broadband spectra, are useful for a range of applications within Thorlabs' Cerna microscopy platform:

• Fluorescence Microscopy
• Reflected Light Microscopy
• Near Infrared/Infrared (NIR/IR) Microscopy

They are recommended as epi-illumination sources for a Cerna microscope, and can be used with the CSE2100 or CSE2200 Epi-Illuminator Modules.

Mounting a Solis LED onto an epi-illuminator module requires an externally SM2 (2.035"-40) threaded adapter with a male D3T dovetail (Item # SM2A56). First, thread the adapter securely onto the Solis LED. The adapter utilizes the dovetail to attach to the epi-illuminator module; simply insert the adapter and LED into the back of the module, then secure the dovetail with the side setscrew using a 5/64" (2mm) hex key. See the figures to the right for details, and the epi-illuminator module web presentation for additional information about microscope dovetail connections.

Please contact Technical Support to use a Solis LED in a trans-illumination configuration.

Thorlabs offers two options for driving our Solis^® LEDs. The DC20 is a basic option that allows users to control the intensity of their LED using a control knob on the top or via an external TTL signal for modulation. For more advanced applications, our DC2200 drivers provides a touchscreen interface that allows users to control the LED current, select internal or external modulation modes, and more. The table below provides a comparison of key controller features.

Solis® LED Driver Selection Guide
Item #	DC20	DC2200
Photo (Click to Enlarge)
LED Current / Forward Voltage (Max)	1 to 10 A / 5.0 to 14.0 Va	1.0 A / 50.0 Vb 2.0 A / 35.0 Vb 4.0 A / 15.0 Vb 5.0 A / 10.0 Vb 10.0 A / 5.0 Vb
Noise and Ripple (1 Hz to 10 MHz, RMS, Typical)	<400 µA	<100 µA from 0.0 to 4.0 A <200 µA from 4.0 to 10.0 A
Internal Modulation Modes	-	0.1 Hz to 20 kHz (PWMc Mode) 1 µs to 10 s On or Off Time (Pulse Mode) 20 Hz to 100 kHz (Internal Modulation Mode with Sine, Square, Triangle Waveforms)
External Modulation (Arbitrary Waveform)	-	DC - 250 kHz [Small Signal Bandwidth (Sine)]d
TTL Modulation (External)	DC to 1 kHz (Square Wave, PWMc)	DC to ≥18 kHze
LED Control Interface	Knob to Control LED Current, BNC Port for TTL Modulation	Easy-to-Navigate Touchscreen Interface, Brightness and Constant Current Operating Modes, Internal and External Modulation Modes, SMA Port for External Modulation Accepts TTL Signal or Waveform from a Function Generator, USB Interface for Remote Control
Current Limit	Automatically Read and Set from the Solis LED's Internal Memory to Protect the LED from Overdriving
External Software Interface	No	DC2200 GUI
Other Compatible LEDs	-	Mounted Collimated Fiber Coupled MCPCB Mountedf

• The maximum LED current and forward voltage are dependent on each other: the DC20 cannot drive an LED with a 14 V forward voltage at 10 A. The DC20 is compatible with all Solis LEDs and will automatically select the appropriate current/voltage combination for the connected Solis LED.
• For Solis LEDs connected using Terminal 1. The DC2200 can also be used to drive Thorlabs' mounted, collimated and fiber-coupled LEDs, which use a separate terminal and are subject to different current and voltage limitations. See the complete web presentation for details.
• PWM = Pulse Width Modulation
• Small Signal Bandwidth: Modulation not exceeding 20% of full scale current. The driver accepts other waveforms, but the maximum frequency will be reduced.
• Given for an output current at "High" TTL level not exceeding 10% of the selected current range limit.
• Requires the CAB-LEDD1 cable.

Software for the DC2200 Driver

The available software can be downloaded by clicking on the link below.

Software

Software Version 1.0 (July 31, 2015)
Firmware Version 1.3.0 (August 26, 2020)

GUI software, firmware, and firmware upgrade wizard downloads for the DC2200.