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d2:dbr_laser [2016/11/28 23:31] – [Specifications] Michael Radunskyd2:dbr_laser [2022/09/08 21:50] (current) – external edit 127.0.0.1
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 =====Description===== =====Description=====
 +
 +<WRAP center round box 60%>
 +| {{ :warning-sign.png?200&nolink }}    | The D2-100 laser module is factory aligned.  It is not advised that the user attempts to re-align the laser in the field.  If the laser becomes misaligned, please return the unit to the factory for realignment.  |
 +
 +</WRAP>
  
 The DBR laser module is comprised of a distributed feedback (DBR) laser diode in a precision temperature-controlled housing with beam conditioning optics and an optical isolator.  DBR laser diodes are fabricated with the feedback grating patterned directly over the gain section of the diode.  They are highly immune to vibrations and by virtue of a very short cavity (~ 1 mm), they can be current tuned over more than 50 GHz.  The result is a robust laser capable of very fast servo control for easy locking to atomic transitions.  The module contains no moving parts or piezo-electrics and is therefore inherently robust and rugged. The DBR laser module is comprised of a distributed feedback (DBR) laser diode in a precision temperature-controlled housing with beam conditioning optics and an optical isolator.  DBR laser diodes are fabricated with the feedback grating patterned directly over the gain section of the diode.  They are highly immune to vibrations and by virtue of a very short cavity (~ 1 mm), they can be current tuned over more than 50 GHz.  The result is a robust laser capable of very fast servo control for easy locking to atomic transitions.  The module contains no moving parts or piezo-electrics and is therefore inherently robust and rugged.
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 <imgcaption DBR_Exploded|Exploded view of the DBR subassembly> <imgcaption DBR_Exploded|Exploded view of the DBR subassembly>
 {{ :d2:d2-100:dbr-inside-exploded-view.png?nolink&300 |}}</imgcaption> {{ :d2:d2-100:dbr-inside-exploded-view.png?nolink&300 |}}</imgcaption>
 +
 +We use [[https://www.photodigm.com|Photodigm]] Spectroscopy-Certifed<sup>TM</sup> DBR lasers. \\
 +[[https://www.photodigm.com|{{:d2:d2-100:photodigm_logo.png?direct&200|}}]]
  
 =====Purchase Includes===== =====Purchase Includes=====
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 |Stage 2 Temperature of DBR Laser Diode|>15°C and <40°C| |Stage 2 Temperature of DBR Laser Diode|>15°C and <40°C|
 |Laser Diode Current|See datasheet included with your laser.| |Laser Diode Current|See datasheet included with your laser.|
 +</WRAP>
 +
 +<WRAP center round important 60%>
 +The laser should never be operated at a temperature below the dew point temperature for your laboratory conditions.  Condensation can form on the laser chip and/or mounting hardware resulting irreparable damage.
 </WRAP> </WRAP>
  
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 <WRAP center round box 700px> <WRAP center round box 700px>
 ^    ^  Min.  ^  Typical  ^  Max.  ^  Units  ^ ^    ^  Min.  ^  Typical  ^  Max.  ^  Units  ^
-^Wavelength|  767, 770, 780, 795,\\ 852, 895, 1064, or 1083((Contact factory for other wavelengths))  |  nm  |||+^Wavelength|  767, 770, 780, 795,\\ 852, 895, 1064, or 1083((Contact factory for other wavelengths))  |||  nm  |
 ^Output power|  30  |  40  |  50  |  mW  | ^Output power|  30  |  40  |  50  |  mW  |
 +^-HP1 Output power|  100  |  Wavelength Dependent  |  200  |  mW  |
 ^Beam diameter|  0.8  |  1.1  |  1.7  |  mm\\ (1/e<sup>2</sup> dia.)  | ^Beam diameter|  0.8  |  1.1  |  1.7  |  mm\\ (1/e<sup>2</sup> dia.)  |
 ^Polarization|  Horizontal  |||    | ^Polarization|  Horizontal  |||    |
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 ^Temperature range \\ Stage 1, housing \\ Stage 2, laser|  \\ 15 \\ 0  |  \\ 20\\ 15  |  \\ 40\\ 50 <sup>(</sup>((Operation above 40° C can reduce the lifetime of the laser diode))  |  \\ °C  | ^Temperature range \\ Stage 1, housing \\ Stage 2, laser|  \\ 15 \\ 0  |  \\ 20\\ 15  |  \\ 40\\ 50 <sup>(</sup>((Operation above 40° C can reduce the lifetime of the laser diode))  |  \\ °C  |
 ^Temperature stability|  See [[d2:laser_controller|Laser Controller]]  |    | ^Temperature stability|  See [[d2:laser_controller|Laser Controller]]  |    |
-^[[http://www.analogtechnologies.com/ath10kr8.html|Analog Technologies ATH10KR8 Thermistor]]||<html> &nbsp;&nbsp; </html>| 10k | Ω | +^[[http://www.analogtechnologies.com/ath10kr8.html|Analog Technologies ATH10KR8 Thermistor]]| | | 10k | Ω | 
-^Analog Technologies ATH10KR8 Beta||<html> &nbsp;&nbsp; </html>| 3480 | K | +^Analog Technologies ATH10KR8 Beta| | | 3480 | K | 
-^Analog Technologies ATH10KR8 T<sub>0</sub>((Temperature at which thermistor reads 10 kΩ))||<html> &nbsp;&nbsp; </html>| 25 | °C |+^Analog Technologies ATH10KR8 T<sub>0</sub>((Temperature at which thermistor reads 10 kΩ))| | | 25 | °C |
 ^Safety Class|  3B  |    | ^Safety Class|  3B  |    |
-^Beam height|  0.95  |  inches  ||+^Beam height|  0.95  |||  inches 
-^Total package Size \\ (L x W x H)|  3.75 x 4 x 2  |  inches  |+^Total package Size \\ (L x W x H)|  3.75 x 4 x 2  |||  inches  |
 </WRAP> </WRAP>
  
  
-=====Inputs, Outputs, and Controls=====+=====Laser Control Signals=====
  
-**Vertical and horizontal pointing **+==== Temperature Control Loops ====
  
-The vertical and horizontal alignment of the laser system is factory set and should not need adjustment.  However, if your specific application requires it or the system is misaligned, the DBR subassembly has adjustments to steer the beam for alignment to the spectroscopy module or other modules.  The beam pointing is adjusted by loosening the three lock screws ½ turn past the crack point and adjusting the x and y positioning set screws on the top and left side (facing out along the laser beam) of the module (see <imgref DBR_lock_screws>). For more detailed instructions, see  the [[#aligning_the_dbr_laser_module|alignment section]]. +The connections to the TECs and thermistors are made to an 8-pin Hirose connector (see <tabref TECconnectortable> for identity of connectors).  The pin definitions are:
- +
- +
-<imgcaption DBR_lock_screws|Lock screws and beam pointing controls> +
-{{ :d2:d2-100:dbr-lock-screws.png?nolink&300 |}} +
- +
-</imgcaption> +
- +
- +
-**Beam Conditioning** +
- +
-The collimation of the output beam is set at the factory and should not be adjusted unless absolutely necessary.  Remove the isolator subassembly from the baseplate with the 4 screws accessible from the bottom.  The collimation can be adjusted by turning the lens.  A spanner wrench can be inserted into the two holes on the side of the black lens holder to adjust the lens.   +
- +
-Laser diodes all have astigmatism, which means the horizontal and vertical axis have different foci.  Vescent uses a powerful asphere with a short focal length and an anamorphic prism pair to create a small diameter circular beam. This reduces the costs of the isolator and other downstream modules by reducing the clear aperture requirements.  While the aspheres and anamorphic prisms produce a circular beam, astigmatism dictates that a single lens will not simultaneously collimate both orthogonal axes of the beam with the result that in the far field the beam is again elliptical. +
- +
-The far-field pattern is the most important for ascertaining the quality of the diode output.  The near-field pattern often shows stray light from the diode waveguide and ASE that doesn't propagate as part of the primary beam.  However, aberrations and beam clipping due to an insufficient lens NA will show up as fringes-on the far field pattern.  Vescent has taken care in the design of the DBR laser module to keep aberrations and clipping to a minimum, resulting in a clean beam in the far field. +
- +
-**Cable Connector** +
- +
-The connections to the TECs and thermisters are made to an 8-pin Hirose connector (see <tabref TECconnectortable> for identity of connectors).  The pin definitions are:+
  
 <WRAP center round box 300px> <WRAP center round box 300px>
 +<tabcaption 105_pinout| Pin assignment for 8-pin Hirose connector>
 ^  Pin  ^  Signal  ^ ^  Pin  ^  Signal  ^
 |  1  |  TEC1+  | |  1  |  TEC1+  |
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 |  7  |  Rth2  | |  7  |  Rth2  |
 |  8  |  Rth2-RTN  | |  8  |  Rth2-RTN  |
 +</tabcaption>
 </WRAP> </WRAP>
 <WRAP round center box 320px> <WRAP round center box 320px>
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 NOTE:  Earlier models use a push-pull connector for the 8-pin connector to the DBR module.  To remove take care to apply opposition forces with the thumb and forefinger knuckles against the housing.  Excessive force could displace the output beam and require realignment. NOTE:  Earlier models use a push-pull connector for the 8-pin connector to the DBR module.  To remove take care to apply opposition forces with the thumb and forefinger knuckles against the housing.  Excessive force could displace the output beam and require realignment.
  
-**Laser Current (SMA)**+==== Laser Current (SMA) ==== 
 +<WRAP center round important 60%> 
 +Never connect or disconnect the D2-100 Laser to a laser controller that is energized.  Always power down the laser controller completely before making connections to this laser. 
 + 
 +Always make sure to make a snug connection between the D2-100 and the current-carrying SMA cable, and between the cable and the laser controller. 
 +</WRAP>
  
 Current is provided to the DBR chip through an SMA connector.  The central conductor of the SMA connects to the laser anode, and the shield connects to the laser cathode.  //This is a direct, unprotected connection to the DBR chip, so care must be taken to avoid ESD damage.// Current is provided to the DBR chip through an SMA connector.  The central conductor of the SMA connects to the laser anode, and the shield connects to the laser cathode.  //This is a direct, unprotected connection to the DBR chip, so care must be taken to avoid ESD damage.//
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-=====Aligning the DBR Laser Module=====+==== Safety Information ==== 
 +<WRAP center round important 60%> 
 +The D2-100 is only specified for use with the Vescent D2-105 laser controller, and with cables provided by Vescent. 
 +</WRAP> 
 + 
 +The D2-100 is a Class 3B CW laser product under the guidelines provided in IEC 60825-01:2014. It has no serviceable parts, and should not be disassembled in the field under any circumstance. Viewing of the beam, either directly, with viewing optics, or from a specular reflection can cause damage to the eye, and should be avoided.  
 + 
 +The D2-100 is available in many wavelengths, listed above, as well as in a high powered configuration. The maximum specified output of any D2-100 is 200mW under normal operating conditions. However, if provided with too much current, some of the high powered (-HP1) lasers can reach 300mW before experiencing critical optical damage. The beam divergence is < 0.08° in both x and y.  
 + 
 +The Maximum Permissable Exposire (MPE) for the D2-100 is 14.45 W*m<sup>-2</sup>, calculated with a >10s exposure time, and the Nominal Ocular Hazard distance is roughly 100m. Proper eye protection for the D2-100 is highly wavelength dependent. We recommend [[https://noirlaser.com/lasershields?input1=780&input2=0&input3=0|this]] online tool, provided by NoIR, and an OD value of at least 3+ for the selected wavelength when choosing the correct eye protection. 
 + 
 +There are four safety stickers present on the D2-100. The first, located on the side of the isolator module, is the explanatory sticker, which states the classification of the laser, and several safety instructions. It reads: "Invisible laser radiation avoid exposure to beam class 3B laser product"
 + 
 +<imgcaption safety_sticker|Reproduction of Explanatory label on the D2-100. \>{{ :d2:d2-100:sticker.png?200 |}}</imgcaption> 
 + 
 +On the side of the isolator module opposite the explanatory sticker is a sticker which lists the maximum possible output of the laser in mW, the wavelength of the laser, and the name of the IEC certification standard to which the laser adheres. 
 + 
 +<imgcaption IEC_sticker|Reproduction of second Explanatory label on the D2-100.>{{ :d2:d2-100:needed_sticker.png?200 |}}</imgcaption> 
 + 
 +On the top of the D2-100, near the laser aperture, is a "Laser Aperture" sticker. 
 + 
 +<imgcaption aperture|Reproduction of Laser Aperture sticker on the D2-100.>{{ :d2:d2-100:aperature.png?200 |}}</imgcaption> 
 + 
 +Finally, on the sliding beamstop adjacent to the laser aperture, is a triangular laser radiation warning sticker.
  
-The module should not need adjustments, but if necessary the following procedure can be used to fine tune the beam positioning.+<imgcaption triangle|Laser Radiation Warning sticker on the D2-100.>{{ :d2:d2-100:triangle.png?200 |}}</imgcaption>
  
-  - Loosen the three locking screws on the back of the DBR module ½ turn past the crack point. +There is only one laser aperture on the D2-100located on the front with the isolator as shown in (<imgref DBR_laser>). 
-  With a 0.050" Allen driveradjust the vertical adjustment setscrew on the top of the DBR housing to level the beam. +
-  - Adjust the horizontal adjustment 4-40 set screw on the left side of the DBR housing (See <imgref DBR_lock_screws>)+
-  - Alternatively, use the spectroscopy module as a beam target.  Place the spectroscopy module as far down the table as possible, bolt it down, and center the beam to the input hole. +
-  - Gently retighten the three locking screws.+
  
 +Safe operation of the D2-100 necessitates that a compliant laser driver be used to supply a current to the diode. It is important to always correctly set the current limit on any laser driver before energizing the laser system. The D2-100 is a Cathode-Ground laser, and requires a DC current between 0mA and 500mA((Specific current for each laser supplied with test documentation)) to be safely turned on. The connector used to supply current to the D2-100 is a female SMA, which requires a male SMA cable for compatibility.
d2/dbr_laser.1480375871.txt.gz · Last modified: 2021/08/26 14:26 (external edit)