CO2 Basic

The Diamond laser series is a modular, RF excited, sealed industrial CO2 modulated laser. The Diamond K-150/K-200/K-250 Basic System consists of a laser head, RF amplifier, and Diamond digital interface (DDI).

Several options are available for this Diamond system including:

• Electrical shutter and aiming beam
• Remote control unit for easy interface to controllers
• DC power supply
• Beam delivery hardware

Head Cover Light On - Diamond Basic/PP

1. Verify that the head cover is installed properly.
2. If the light is still on remove the cover and install interlock defeat, which is shipped in the maintenance kit. If the indicator goes off when interlock defeat is installed, verify that the head cover and interlock pins are making contact. Clean contact area if necessary.
3. If light is still on replace the headboard per procedure in the operator’s manual.
4. If after verifying and/or correcting the checklist items the system is still not operating contact Coherent Technical Support at 1-800-367-7890 or your local service representative for assistance.

Head Thermal Light On - Diamond Basic/PP

1. Verify that the cooling water temperature is within specifications for your laser model as stated in the operator’s manual.
2. Verify that the cooling water flow through the laser system is within the specifications for your laser model as stated in the operator’s manual.
3. Check continuity of thermal switch located on the shutter blade. Disconnect the shutter cable from the shutter assembly. Measure the resistance between pins 6 and 12 at the connector. The acceptable value is 20 ohms when the shutter blade is less than 35ºC. Click here for illustration
4. Place a Jumper between R9 and TP1 on the headboard. If the head thermal light goes off, then replace the shutter cable. If light stays on replace the headboard per the instructions in the operator’s manual; if light is still on replace the power module. Click here for illustration
5. If after verifying and/or correcting the checklist items the system is still not operating contact Coherent Technical Support at 1-800-367-7890 or your local service representative for assistance.

Laser System Doesn’t Turn On - Diamond Basic/PP

Background information: The laser system has an interlock circuit that the customer/integrator can interface to. This interlock circuit prevents the laser from turning on if a safety requirement is not met. The interlock circuit uses a 5 VDC power supply that turns on the main 48 VDC power supply when all of the interlocks, external and internal are properly connected.

1. Verify that the input voltage selector on the power module is set to the correct input line voltage for your facility. See Chapter titled “Utility Requirements and System Installation”, paragraph titled “Changing Input Voltage for Power Module” in the Operator’s Manual.Click here for Performance Package illustration Click here for Basic Package illustration
2. If the laser system has external safety interlocks installed, verify that these interlocks are okay.
3. Verify that the power module is connected to the input line voltage and that the input line voltage is ok. See Chapter titled “Utility Requirements and System Installation”, table titled “Utility Requirements” in the Operator’s Manual for more information on input line voltage requirement.
4. Verify that all cables are connected properly. Click here for illustration.
5. Verify that the interlock + connector (15 pin DB connector) is plugged into J11 on the remote control unit. Click here for illustration.
6. Verify that all key switches are on. Click here for illustration

Basic troubleshooting:

1. Verify that the J7 user connector (9 pin DB connector) is plugged into the DDI box.

Performance Package troubleshooting:

1. Verify that the power module fuse is okay.
2. Verify that the interlock connector (9 pin DB connector) is plugged into the power module. Click here for illustration
3. Verify that the emergency stop switch is not pushed in.

The Diamond laser series is a modular, RF excited, sealed industrial CO2 modulated laser. The Diamond K-150/K-200/K-250 Basic System consists of a laser head, RF amplifier, and Diamond digital interface (DDI).

Several options are available for this Diamond system including:

• Electrical shutter and aiming beam
• Remote control unit for easy interface to controllers
• DC power supply
• Beam delivery hardware

The Diamond laser series is a modular, RF excited, sealed industrial CO2 pulsed laser. The Diamond K-150/K-200/K-250/K-500 Performance Package consists of a laser head, a power module, a remote control unit and interconnection cables. The power module, which can interface with an external controller, contains:

• RF amplifier
• DC power supply
• Diamond digital interface (DDI) board
• Internal heat exchanger

The laser system plasma tube will have zero, one, or two Brewster windows depending on the system type. Sealed mirror systems may have one window or no accessible windows. Other system types have two windows.

Great care should be taken when cleaning the plasma tube Brewster windows. A scratch on the window surface may degrade performance to the extent that the tube must be replaced. The Brewster window is located in a sealed cavity and rarely needs to be cleaned. Turn off the laser system before cleaning the Brewster window. Extremely high voltage is present adjacent to the window when the laser is on. This voltage may cause serious shock to the operator, or if shorted to ground may result in catastrophic damage to the plasma tube and/or power supply.

Cleaning Procedure
For the front window, slightly rotate the bellows back and forth while sliding the dust shield/bellows towards the front of the head to expose the Brewster window. There will be some resistance when sliding the bellows because the Teflon O-rings produce seals to the window stem and aperture transition tube.

1. Close the intracavity shutter and position an appropriate power meter detector head in front of the laser system. Reopen the shutter and verity that the detector head has been properly positioned. The power meter detector head should be positioned as close to the laser head output aperture as possible. Care should also be taken to assure that a beam dump captures all back reflections from the detector surface.
2. Depress the “Tune” button on the laser system remote control. This will place the laser system in the fixed Current mode of operation and disable PowerTrack, if equipped. Using the HR horizontal and vertical tilt controls optimize the laser system output power. Record the power, and if possible, the transverse laser mode.
3. Turn off the laser key switch, but maintain facility electrical power.
4. Remove the appropriate laser head sub-cover and expose the plasma tube Brewster window. For the rear window, slightly rotate the bellows back and forth while sliding the dust shield/bellows towards the rear of the head to expose the Brewster window. There will be some resistance when sliding the bellows because the Teflon O-rings produce seals to the window stem and aperture transition tube.
5. Clean the Brewster window using the Hemostat and Lens Tissue method. Make a single wipe with a smooth continuous motion using light pressure. Do not reuse the lens tissue. Wipe in the correct direction as follows.
   • Always wipe the window TOWARD the dust shield. Never wipe the window toward the center of the laser.
   • At the start of the cleaning stroke, the lens tissue should be positioned just to the inside of the window edge as illustrated in the figure below. The edge of the window can be sharp, and chips of the window material may break off from the cleaning process. If these chips are dragged across the Brewster window, the surface of the window may be scratched
   • After cleaning the window, wait approximately 15-seconds for all solvent vapors to dissipate. Replace the bellow/dust shield using a slight back-and-forth rotational motion to overcome seal resistance while sliding . Ensure that the bellows are not overextended and have a good seal on both the window stem and the aperture transition tube. Extreme care should be taken to ensure that no intracavity components come in contact with the Brewster window.
   • Replace the laser head sub-cover and restart the laser system (key On).
   • Depress the Tune button on the remote and re-peak the laser system. Verify that the power is equal to or greater than the levels recorded before cleaning. If the output power is lower than previously measured the Brewster window should be re-cleaned. Do not clean another optic until all power levels are regained or exceeded.
   • Once the laser system is optimized, re-press the Tune button. If equipped, verify that the PowerTrack LED is illuminated. If the order of the transverse mode was the cause for cleaning, verify that the mode is as expected and that the system aperture and regulation mode are properly set for your application.

Optic cleaning is not a required component of a regular laser system maintenance schedule. Optics should only be cleaned as a corrective action for marked power decrease or poor mode quality. Optics should not be cleaned unless signs of contamination are clearly visible on the optic surfaces. Unnecessary cleaning will shorten the life span of the optical coating.

Optics and optic coatings can be easily damaged. Never touch the optical surfaces with bare skin, hemostats, or materials other than lens tissue.

The Hemostat and Lens Tissue Method

1. If applicable, place the laser system in Current control mode of operation. For Ion laser systems disengage PowerTrack if this option is available. Record the laser system output power, and output mode characteristics if applicable. Turn off the laser system, or block the pump laser beam if the optic to be cleaned is in an oscillator or amplifier.
2. Inspect the system optics for contamination. Clean an optic only if contamination is clearly visible. A bright flashlight, held a glancing angle of incidence with respect to the optical surface, can help to identify contaminated optics.
3. Fold a lens tissue into a 1-cm (3/8-in.) wide strip, being careful not to touch the portion of the tissue that will contact the optic.
4. Fold this strip upon itself twice and grasp near the fold with clean hemostats as shown in the figure below.
5. Place a few drops of Methanol on the fold and shake off the excess.
6. Make a single swipe across the surface of the optic. Do not re-use the lens tissue as particles of dust and other contaminates picked up from the surface of the optic may scratch if dragged across with a second swipe.
7. Turn on the laser system, or unblock the pump laser beam. Using only the mount tilt controls of the optic that was cleaned, optimize the performance of the laser system. Do not clean another optic until the system performance meets or exceeds that previously recorded.

On some systems the high reflector (HR) is sealed to the tube and is not accessible. Do not attempt to extract and clean the optic. An example of a sealed mirror tube is shown in the figure below.

Handle laser optics with care. A scratch, trace of dirt, or film will diminish the laser’s efficiency. Before cleaning optics, be sure that your hands are clean and that a clean, cushioned work surface is available.

Optics and optic coatings can be easily chipped or scratched. To prevent damage when removing or replacing mirrors, always grasp the optic by the outer edge. Never touch the optical surfaces with your bare skin, the hemostats, or materials other than lens tissue. Only fresh (dry) spectroscopic grade Methanol should be used to clean optics.

Cleaning Procedure

1. Close the intracavity shutter and position the appropriate power meter detector head in front of the laser system. Reopen the shutter and verity that the detector head has been positioned properly. The power meter detector head should be positioned as close to the laser head output aperture as possible. Care should also be taken to assure that a beam dump captures all back reflections from the detector surface.
2. Depress the “Tune” button on the laser system remote control. This will place the laser system in the fixed Current mode of operation and disable PowerTrack, if equipped. Using the HR horizontal and vertical tilt controls optimize the laser system output power.
3. Record the power, and, if possible, the transverse laser mode.
4. Close the intracavity shutter, remove the knurled cap securing the multiline optic and holder, and remove the mirror holder (see figure above). Inspect the optic for contamination and damage. The optic should be cleaned only if contamination can clearly be seen.
   • A bright flashlight, held at a glancing angle of incidence with respect to the optical surface, is very helpful in identifying contaminated optics.
   • Breathe on the optic to determine if there is any damage to the coating. The surface should fog with no discoloration. If discoloration appears the coating has been damaged and the optic must be replaced.

5. If required, clean the exposed (coated) surface of the high reflector using the Drop and Drag method. It should not be necessary to remove the optic from the holder.
6. Reinstall the multiline mirror holder and knurled cap, open the intracavity shutter, and optimize the output power using the HR horizontal and vertical tilt controls. The observed power should be equal or greater than that previously measured. Do not adjust any other optics or controls until this is the case. If the previous power can not be achieved:
   • Remove the multiline holder and verify that the optic is properly seated, and was not been damaged by the cleaning or removal/reinstallation process.
   • Verify that that fresh spectroscopic grade methanol is being used, and re-clean the optic. Note that over time methanol will absorb water from the air, and this water will leave a film on an optical coating or surface.

7. Once the laser system is optimized, re-press the Tune button. If equipped, verify that the PowerTrack LED is illuminated. If the order of the transverse mode was the cause for cleaning, verify that the mode is as expected and that the system aperture is set properly for your application.

For diode pumped laser systems (e.g., Verdi, AVIA, MBD-200, Azure, Vitesse, etc.) the optical transport fiber is sealed within the diode (FAP-I) assembly and should not require cleaning under normal operating conditions. When replacing the FAP-I assemblies of these systems, and for optical transport fibers in general, the optical surface should always be viewed with a magnifier to verify the presence of contamination before cleaning. Do not clean the fiber if there is no visible contamination.

The end of the fiber optic cable constitutes an optical surface. Do not allow the end of the fiber optic cable to make contact with any surface, including your hands.

Optics and optic coatings can be chipped or scratched easily. Wear finger cots, or powder free surgical gloves, while handling fiber optic cables. Only fresh (dry) spectroscopic grade Methanol should be used as a cleaning solvent. Do not use Acetone as a cleaning solvent on the fiber optical surfaces. It will dissolve the matrix which supports the fiber, and permanently destroy the optical transport fiber.