Tungsten-Halogen Light Sources

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The measured spectral power distribution for the SLS301 Light Source.

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The control unit for the SLS301 source.

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The back port provides access to uncollimated light at longer wavelengths.

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The back of the SLS301 source with the removable plate taken out to incorporate 30 mm cage rods and fixed optic holder.

• 360 - 3800 nm Stabilized Light Source
  • 360 - 2700 nm through the Front Lens
  • 360 - 3800 nm through the Back Port
• >1.6 W Output Power Collimated in a Ø35 mm Beam
• Closed-Loop Control for High Stability
  • Power Fluctuations of 0.05% within 1 Hour
  • Color Temperature Stability: ±15 K
• Low Optical Drift: 0.01% per Hour / 0.1% per °C
• 30 mm and 60 mm Cage System Compatible
• Manual Shutter

Thorlabs' SLS301 Stabilized Quartz Tungsten-Halogen Light Source provides a constant intensity, >1.6 W blackbody radiation spectrum between 360 and 3800 nm. An internal feedback system is employed to achieve a highly stable power output (0.05% fluctuation). The >1.6 W output is collimated into a Ø35 mm beam for free-space applications. Since the blackbody spectrum spans both the visible and near-infrared spectral ranges, this source is ideal for integration into optical measurement equipment, such as back illumination for a test target as part of a detector calibration system. It can also be used as an illumination source in a white light interferometer for applications such as mapping surface structure.

The SLS301 is shipped with a factory-installed collimation lens. This configuration provides >1.6 W of free-space, collimated output power in a Ø35 mm beam. The lens tube of the collimation lens features internal SM2 (2.035"-40) threading for easy integration of SM2-threaded parts, including the liquid light guide adapters sold below. A knob on the front of the housing allows a manual shutter to block the output if desired.

The front face of the housing can integrate a 60 mm cage system, while the back face has a removable plate with four 4-40 taps to incorporate a 30 mm cage system centered around an SM1-threaded (1.035"-40) aperture. It should be noted, however, that the output from the back face is not collimated. This additional output is ideal for creating a reference signal, or to monitor the output of the SLS301 source without interfering with the Ø35 mm collimated beam.

The included controller, pictured above, has three LED indicator lights for temperature, lamp status, and lifespan. During normal operation, all three will be green. If the controller becomes overheated, the "Temperature" indicator will switch to red and the source will be automatically shut off. The "Lamp Status" indicator will show green if the correct lamp is installed in the SLS301 source, or red if no lamp is present or if the wrong lamp is installed. The "Lifespan" indicator shows yellow once the lamp reaches 75% of its lifespan and red once it reaches 100%.

The large housing design of the SLS301 source allows for the safe dissipation of thermal energy produced by the 150 W lamp. When used for an extensive amount of time, the housing can heat up to ~60 °C, so extensive contact should be avoided. Replacement lamps are sold below.

If a higher color temperature is desired, our color-balancing filters can be used to attenuate red light from the SLS301 light source while passing blue light. This results in a beam with a higher color temperature and lower total power.

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The measured spectral power distribution for the SLS302 Light Source.

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The control unit for the SLS302 source.

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A rear concave mirror on a kinematic mount maximizes output power.

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The front of the SLS302 source supports integration with 60 mm cage systems.

• 360 - 2500 nm Stabilized Light Source
• >10 W Output Power Collimated in a Ø46 mm Beam
• Closed-Loop Control for High Stability
  • Power Fluctuations of 0.05% within 1 Hour
  • Color Temperature Stability: ±15 K
• Low Optical Drift: 0.01% per Hour / 0.1% per °C
• User-Adjustable Lamp Position
  • ±3 mm in X and Z Axes
  • ±2.5 mm in Y Axis
• 60 mm Cage System Compatible
• Manual Shutter

Thorlabs' SLS302 Stabilized Quartz Tungsten-Halogen Light Source provides a constant intensity, >10 W blackbody radiation spectrum between 360 and 2500 nm. An internal feedback system is employed to achieve highly stable output power (0.05% fluctuation). The high-power output is collimated into a Ø46 mm beam for free-space applications. Since the blackbody spectrum spans both the visible and near-infrared spectral ranges, this source is ideal for integration into optical measurement equipment, such as back illumination for a test target as part of a detector calibration system. It can also be used as an illumination source in a white light interferometer for applications such as mapping surface structure.

The SLS302 source is shipped with a factory-installed collimation lens. The lens tube of the collimation lens features internal SM2 (2.035"-40) threading for easy integration of SM2-threaded parts. Please note that the SLS302 source should not be used with our liquid light guides without active cooling of the LLG to prevent overheating and burning of the LLG tips. The front face of this source can also integrate a 60 mm cage system, as shown in the image to the right. A knob on the front of the housing allows a manual shutter to block the output if desired.

A concave mirror is mounted at the rear of the unit on a kinematic mount. Although the mirror is factory-aligned to maximize power output, three knobs on the rear panel allow the user to adjust the pitch, yaw and Z mirror position as needed. In addition, the housing also has a knob towards the bottom of each of three sides for adjusting the lamp position, which can be translated ±3 mm in the X and Z axes, as well as ±2.5 mm in the Y axis. As a result of these added mounting features, the ~142 mm beam height of the SLS302 source is approximately 30 mm higher than the other light sources features on this page.

The included controller, pictured above, has three LED indicator lights for temperature, lamp status, and lifespan. During normal operation, all three will be green. If the controller becomes overheated, the "Temperature" indicator will switch to red and the source will be automatically shut off. The "Lamp Status" indicator will show green if the correct lamp is installed in the SLS302 source, or red if no lamp is present or if the wrong lamp is installed. The "Lifespan" indicator shows yellow once the lamp reaches 75% of its lifespan and red once it reaches 100%.

The large housing design of the SLS302 source allows for the safe dissipation of thermal energy produced by the 150 W lamp. When used for an extensive amount of time, the housing can heat up to ~60 °C, so extensive contact should be avoided. Replacement lamps are sold below.

If a higher color temperature is desired, our color-balancing filters can be used to attenuate red light from the SLS302 light source while passing blue light. This results in a beam with a higher color temperature and lower total power.

• Couples the Output of the Broadband Light Source into a Liquid Light Guide (LLG)
  • Active Cooling of LLG is Necessary if Used with SLS302 High-Power Light Source
• Adapters Designed for 185 nm - 2.1 µm or 350 - 700 nm Wavelength Range
• Compatible with Ø3 mm and Ø5 mm Core Liquid Light Guides
• SLSLLG2 Includes Integrated Electronic Shutter with External Controller

These Liquid Light Guide Adapters are designed to quickly and easily integrate with the SLS301 light source to couple the output into Ø3 mm or Ø5 mm core Liquid Light Guides (LLGs). The SLS302 high-power light source should not be used with liquid light guides without active cooling of the LLG to prevent overheating of the LLG tips. The adapters contain a collimating lens and are externally SM2 threaded (2.035"-40), allowing them to directly thread onto the collimation lens assembly without the need to remove or adjust either lens.

The SLSLLG1 is designed with an uncoated collimating lens, which provides a wide operating range from 185 nm - 2.1 µm. For superior performance from 350 nm - 700 nm, the SLSLLG2 and SLSLLG3 lenses use an AR-coated lens that provides improved coupling efficiency in this wavelength range. Transmission of wavelengths longer than 800 nm through the LLG for longer than an hour may result in permanent damage to the LLG tip; to reduce damage during extended use, incorporate a filter to limit transmission of IR wavelengths.

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The SLSLLG2, with a liquid light guide, attached to the SLS402 Light Source.

The SLSLLG2 features an integrated diaphragm shutter and an external controller that can operate at continuous frequencies up to 10 Hz and burst frequencies up to 15 Hz. For more information on the integrated shutter, please refer to the manual.

All liquid light guide adapters come with the AD3LLG adapter preinstalled, making them compatible with Ø3 mm LLGs out of the box. They are also shipped with the Ø5 mm LLG-compatible AD5LLG adapter, which can be swapped in by unthreading the AD3LLG and replacing it with the AD5LLG.

• Replacement Quartz Tungsten-Halogen Lamp for SLS301 or SLS302 Stabilized Light Sources
• Electrical Power: 150 W
• Color Temperature: 3400 K (Refer to the Graphs Tab for Typical Spectra)
• Ozone Free Lamp

This SLS301B replacement lamp is compatible with the SLS301 and SLS302 light sources. Please see the Lamp Replacement tab for detailed instructions.

Note: We strongly recommend wearing gloves when replacing the lamps in our light sources to prevent skin oils from being deposited onto them. If you suspect the lamp is dirty, carefully clean it with alcohol before connecting it to a power supply.