|Laser Diode Selection Guide|
|Shop by Wavelength||UV (375 nm)|
Visible (404 nm - 690 nm)
NIR (705 nm - 2000 nm)
MIR (3.42 µm - 9.55 µm)
|Shop by Package / Type||TO Can (Ø5.6, Ø9, and Ø9.5 mm)|
TO Can Pigtail (SM)
TO Can Pigtail (PM)
TO Can Pigtail (MM)
Single-Frequency ECL Butterfly Package
Chip on Submount
MIR Fabry-Perot Two-Tab C-Mount
MIR DFB Two-Tab C-Mount
|Laser Diode Tutorial|
|Clicking this icon below will open a window that contains item specific specifications and mechanical drawings.|
This web page contains Thorlabs' UV laser diode with a center wavelength at 375 nm. The table below lists basic specifications to help you narrow down your search quickly. The blue Info button next to the part number within the table opens a pop-up window, which contains in-depth information regarding the diode.
This 375 nm diode is available pre-mounted in the S05LM9 laser diode mount. We have categorized the pin configuration of TO-packaged diodes in to standard A, B, C, D, E, F, G and H pin codes (see image below). This pin code allows the user to easily determine compatible mounts. TO-packed diodes are the most widely supported diodes by our product line.
While the center wavelength is listed for the diode, this is only a typical number. The center wavelength of a particular diode varies from production run to production run, thus the diode you receive may not operate at the typical center wavelength. Diodes can be temperature tuned, which will alter the lasing wavelength.
Please see our Laser Diode Tutorial for more information on laser diodes in general.
Laser diodes are sensitive to electrostatic shock. Please take the proper precautions when handling the device; see electrostatic shock accessories. Fabry-Perot lasers are also sensitive to optical feedback, which can cause significant fluctuations in the output power of the laser diode depending on the application. Members of our technical support staff are available to help you select a laser diode and to discuss possible operation issues.
|IMPORTANT NOTES AND WARRANTY INFORMATION ON LASER DIODES|
|These laser diodes are designated for use solely as components and are not sold as a complete laser product. The purchaser assumes the responsibility to comply with US 21 CFR 1040.10, US 21 CFR 1040.11, and IEC 60825-1, Edition 1.2 with regard to the use of these diodes and their introduction into commerce.|
|Laser Diode Warranty|
When operated within their specifications, laser diodes have extremely long lifetimes. However, most failures occur from mishandling or operating the lasers beyond their maximum ratings. Laser Diodes are highly static sensitive devices. Since Thorlabs does not receive any warranty credit from our laser manufacturers we cannot guarantee the lasers after their sealed package has been opened. Thorlabs will be happy to extend a full refund or credit for any lasers returned in their original sealed package within 30 days of purchase.
Please refer to the LD Operation tab for details on our warranty policies.
|Thorlabs, Inc. Life Support and Military Use Application Policy|
Thorlabs' products are NOT authorized for use as critical components in life support devices/systems or in any military applications without the express written approval of the president of Thorlabs.
Please refer to the LD Operation tab for details on our warranty policies.
Since the output of a laser diode is highly divergent, collimating optics are necessary. Since aspheric lenses do not introduce spherical aberration, they are commonly chosen when the collimated laser beam is to be between one and five millimeters. A simple example will illustrate the key specifications to consider when choosing the correct lens for a given application.
Laser Diode to be Used: L780P010
Desired Collimated Beam Diameter: Ø3 mm (Major Axis)
The specifications for the L780P010 laser diode indicate that the typical parallel and perpendicular beam divergences are 10o and 30o, respectively. Therefore, as the light diverges, an elliptical beam will result. To collect as much light as possible during the collimation process, consider the larger of these two divergence angles in any calculations (i.e., in this case use 30o). If you wish to convert your elliptical beam in to a round one, we suggest using an Anamorphic Prism Pair, which magnifies one axis of your beam.
LD = Laser Diode
Ø = Beam Diameter
Θ = Divergence Angle
From the information above, the focal length of the lens can be determined:
With this information known, it is now time to choose the appropriate collimating lens. Thorlabs offers a large selection of aspheric lenses to choose from. For this application the ideal lens is an -B AR coated molded glass aspheric lens with focal length near 5.6 mm. The C170TME-B (mounted) or 352170-B (unmounted) aspheric lenses have a focal length of 6.16 mm, which will result in a collimated beam diameter (major axis) of 3.3 mm. Next, check to see if the numerical aperture (NA) of the diode is smaller than the NA of the lenses so that the light emitted from the laser diode is not clipped by the lens:
0.30 = NALens > NADiode ~ sin(15) = 0.26
When operated within their specifications, laser diodes have extremely long lifetimes. Most failures occur from mishandling or operating the lasers beyond their maximum ratings. Laser Diodes are among the most static-sensitive devices currently made. Proper ESD Protection should be worn whenever handling a laser diode. Due to their extreme electrostatic sensitivity, laser diodes cannot be returned after their sealed package has been open. Laser diodes in their original sealed package can be returned for a full refund or credit.
Due to their extreme susceptibility to damage from electrostatic discharge (ESD), care should be taken whenever handling and operating laser diodes:
Use an Appropriate Driver:
Laser diodes require precise control of operating current and voltage to avoid overdriving the laser diode. In addition, the laser driver should provide protection against power supply transients. Select a laser driver appropriate for your application. Do not use a voltage supply with a current limiting resistor since it does not provide sufficient regulation to protect the laser.
When setting up and calibrating a laser diode with its driver, use a NIST-traceable power meter to precisely measure the laser output. It is usually safest to measure the laser output directly before placing the laser in an optical system. If this is not possible, be sure to take all optical losses (transmissive, aperture stopping, etc.) into consideration when determining the total output of the laser.
Flat surfaces in the optical system in front of a laser diode can cause some of the laser energy to reflect back onto the laser’s monitor photodiode giving an erroneously high photodiode current. If optical components are moved within the system and energy is no longer reflected onto the monitor photodiode, a constant power feedback loop will sense the drop in photodiode current and try to compensate by increasing the laser drive current and possibly overdriving the laser. Back reflections can also cause other malfunctions or damage to laser diodes. To avoid this, be sure that all surfaces are angled 5-10°, and when necessary, use optical isolators to attenuate direct feedback into the laser.
Laser diode lifetime is inversely proportional to operating temperature. Always mount the laser in a suitable heat sink to remove excess heat from the laser package.
Voltage and Current Overdrive:
Be careful not to exceed the maximum voltage and drive current listed on the specification sheet with each laser diode, even momentarily. Also, reverse voltages as little as 3 V can damage a laser diode.
ESD Sensitive Device:
Currently operating lasers are susceptible to ESD damage. This is particularly aggravated by using long interface cables between the laser diode and its driver due to the inductance that the cable presents. Avoid exposing the laser or its mounting apparatus to ESDs at all times.
ON/OFF and Power Supply Coupled Transients:
Due to their fast response times, laser diodes can be easily damaged by transients less than 1 µs. High current devices such as soldering irons, vacuum pumps, and fluorescent lamps can cause large momentary transients. Thus, always use surge-protected outlets.
If you have any questions regarding laser diodes, please call your local Thorlabs Technical Support office for assistance.
Thorlabs' products are not authorized for use as critical components in life support devices or systems or in any military applications without the express written approval of the president of Thorlabs:
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.
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:
|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.|
|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.|
|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).|
|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.|
|3R||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 are limited to 5 mW of output power in this class.|
|3B||Class 3B lasers are hazardous to the eye if exposed directly. However, diffuse reflections are not harmful. Safe handling of devices in this class includes wearing protective eyewear where direct viewing of the laser beam may occur. In addition, laser safety signs lightboxes should be used with lasers that require a safety interlock so that the laser cannot be used without the safety light turning on. Class-3B lasers must be equipped with a key switch and a safety interlock.|
|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.|
|All class 2 lasers (and higher) must display, in addition to the corresponding sign above, this triangular warning sign|
|Max Drive Current|
|L375P020MLD||375||20||85||Ø5.6 mm||B||S7060R||No||Single Mode|
|*S05LM9 mount included with laser diode|
375 nm, 20 mW, Ø5.6 mm, B Pin Code, Laser Diode w/ S05LM9 Mount