Integrator’s Guide Diamond™ GEM, G & K Lasers 5100 Patrick Henry Drive Santa Clara, CA 95054
Diamond™ GEM, G, &K Laser Integrator’s Guide This document is copyrighted with all rights reserved. Under the copyright laws, this document may not be copied in whole or in part or reproduced in any other media without the express written permission of Coherent, Inc. Permitted copies must carry the same proprietary and copyright notices as were affixed to the original.
TABLE OF CONTENTS Preface ............................................................................................................................ vi U.S. Export Control Laws Compliance .......................................................................... vi Symbols Used in this Document..................................................................................... vi Introduction ................................................................................................................
Diamond™ GEM, G, &K Laser Integrator’s Guide Purge Gas ...............................................................................................................25 Mirages ..................................................................................................................26 Seals for Moving Beams........................................................................................26 Pumping .................................................................................................
LIST OF ILLUSTRATIONS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Warning Logotype (Example) .....................................................................................11 Labels for Removable Housings (Example) ................................................................11 Aperture Warning Label ..............................................................................................11 Certification and Identification Label for a Laser System.......................................
Diamond™ GEM, G, &K Laser Integrator’s Guide Preface This manual contains integration information for the Diamond GEM, G, and K-Series CO2 laser systems. U.S. Export Control Laws Compliance It is the policy of Coherent to comply strictly with U.S. export control laws. Export and re-export of lasers manufactured by Coherent are subject to U.S. Export Administration Regulations, which are administered by the Commerce Department.
Introduction INTRODUCTION The Coherent Diamond™ lasers are a group of compact, high-performance, sealed carbon dioxide (CO2) lasers. They have many packaging advantages over older styles of lasers that greatly facilitate their integration into OEM equipment. They may be installed in any orientation and are able to function while being accelerated. These capabilities, combined with their small physical size, allow Diamond lasers to be installed on robot arms or gantries.
Diamond™ GEM, G, & K, Integrator’s Guide SAFETY General Laser Safety Requirements The information presented in this section is provided to give the System integrator some recommendations on safety requirements when incorporating a laser into an end product. It is by no means complete. The System integrator is responsible for insuring that their system will meet all of the necessary safety regulations and requirements. The manufacture of laser products is Federally regulated, in the U.S.
Safety Your Compliance Responsibilities A “purchaser” is the end user, or one who receives the product for purposes other than resale. If you have purchased the laser to integrate into a system, it is important to note that a given manufacturer and a given purchaser may be part of the same company.
Diamond™ GEM, G, & K, Integrator’s Guide You can obtain ANSI Z 136.1 from: Laser Institute of America 12424 Research Parkway Suite 125 Orlando FL 32826 www.laserinstitute.org You may obtain a listing of ANSI standards directly from: American National Standards Institute 11 West 42nd Street New York, NY 10036 www.ansi.org There are also several consulting companies who can assist you, for a fee, in preparing for CDRH, ANSI and OSHA and EC laser safety compliance.
Safety Basic Performance Requirements All laser products must be designed and built to the lowest hazard class (Class IV most hazardous, Class I not hazardous) possible for the product to still perform its function. In the U.S. this means there are instances when a Class IV product would be allowed (although human exposure to radiation is not permitted). In Europe, for laser processing machines, only Class I machines are permitted.
Diamond™ GEM, G, & K, Integrator’s Guide • Aperture Label – indicating where the radiation is emitted • Warning Logotype – Label stating the nature and class of hazard In the following table, an ‘X’ indicates whether the Diamond GEM, G, & K-series model contains the required feature. An ‘O’ indicates the feature is not provided and the integrator must design and provide one. In any case, even features which are provided by Coherent must be extended or replicated for end users of the final product.
Safety Classification Laser products are classified according to the highest level of laser radiation to which human access is possible during operation only. In this way very high-powered lasers can be enclosed within very low hazard rated laser products, if the radiation access is prohibited during the time of actual operation. Laser Classes are determined by the power and energy level of the accessible radiation.
Diamond™ GEM, G, & K, Integrator’s Guide sary in order for the product to accomplish its function. The laser system must be produced to the lowest possible class. This means if the beam and its reflections can be completely enclosed (practically and feasibly) then they must be enclosed (to the Class I, or light-tight level).
Safety access to radiation accessible during service only. Service only panels of the protective housing need not be interlocked, but should be removable only with the use of a tool. Operation means functions by which the product accomplishes its intended purpose; may include loading/unloading parts, documents, setting/manipulating external controls. Maintenance means functions performed by the user to assure performance (preventative maintenance). Service means, usually, repair.
Diamond™ GEM, G, & K, Integrator’s Guide laser off. The beam attenuator must be available for use at all times during operation. Power switches and key controls do not satisfy the requirement for beam attenuator(s). The beam attenuator must be separate from control or main power. Operating Controls must be located so as to make exposure to radiation unnecessary while the user is manipulating them.
Safety Figure 1. Warning Logotype (Example) Figure 2. Labels for Removable Housings (Example) Figure 3. Aperture Warning Label tions (e.g. December 1989). Codes may be used only if on file with CDRH via model report. Figure 4 is an example of a certification and identification label.
Diamond™ GEM, G, & K, Integrator’s Guide Figure 4. Certification and Identification Label for a Laser System Other Guidance Product compliance also includes requirements for providing certain information to users (customers’ manuals, brochures and data sheets); record keeping and notification; product recall administration; variances and exemptions; and model reporting and notification requirements.
GEM-Series Laser Products DIAMOND GEM-SERIES LASER PRODUCTS There are nine models of Diamond GEM-series lasers. The models are: Table 2.
Diamond™ GEM, G, & K, Integrator’s Guide DIAMOND G & K-SERIES PRODUCTS AND PACKAGES There are nine models of Diamond G & K-series Diamond lasers. The models are: Table 3. Diamond Lasers Models MODEL POWER RATING Diamond G-100 100 watts Diamond G-150 150 watts Diamond K-125i 125 watts Diamond K-150 150 watts Diamond K-225i 225 watts Diamond K-250 250 watts Diamond K-500 500 watts Diamond K2K 145 watts K-series lasers are available in three packages: OEM, Basic and Performance.
Diamond Products and Packages (DDI) is provided to facilitate communication with the power supply. Additional options for this package include an air-cooled DC power supply and a remote control. The Basic package provides everything needed for a fully functional system. In most cases, the power supplies may be installed in the system’s electrical cabinet. Where this is not appropriate, the Performance Package may be used.
Diamond™ GEM, G, & K, Integrator’s Guide FACILITIES REQUIREMENTS The exact facilities requirements for each Diamond laser is detailed in the table titled “Utility Requirements” in the Operator’s Manual for that laser. Since the laser gas is sealed inside the cavity, the lasers require only prime electrical power and cooling (air or liquid) for their operation.
Facilities Requirements The Diamond G & K-series RF power supplies operate on 48 VDC. Coherent offers DC power supplies (included in the K-series Performance Package) that convert incoming AC power to the voltage used by the laser. With the exception of an optional single phase power supply for the G-series lasers, Coherent DC power supplies operate on 3 phase current. These 3 phase power supplies may be damaged by the loss of a phase in the supply current.
Diamond™ GEM, G, & K, Integrator’s Guide AC power AC power cable* AC Power Relay Electronic Controller Refrigerated Recirculator Flow Interlock Switch Coolant Filter Coolant RF Power Supply* RF coaxial cable* Coolant Laser Head* Those items marked with * are supplied by Coherent/DEOS® Figure 5. Recommended Cooling System Functional Block Diagram for GEM-Series Lasers Water Flow Interlock The cooling water flow to Diamond lasers must be monitored at all times.
Facilities Requirements water flow ports. The Diamond Performance Package, which has a water-to-air heat exchanger for the DC power supply, is set up so both the water source and return are connected to the power module. Supply and return lines for the laser head are connected to the module as indicated in Figure titled “Cooling System Diagram” in the Performance Package Operator’s Manual. Shutter On the GEM-series the shutter is customer supplied.
Diamond™ GEM, G, & K, Integrator’s Guide INSTALLATION Diamond lasers may be installed in any orientation, and may be either stationary or mobile. The least favorable orientation is vertical with the beam exiting upwards, because it is easy for contaminants to settle on the laser’s output optic. If this orientation is selected, it is necessary to be very careful to avoid damaging the optic during installation and maintenance, and to supply purge gas at all times afterwards.
Installation it can affect output mode quality. Attaching more than 10 lb. (5 kg) of equipment to the front bezel without providing additional bracing is discouraged. The laser and beam delivery should be connected to the same structure. If they are on separate frames, floor movement can cause system misalignment. Provision must be made for beam delivery alignment. Either the laser or the first beam delivery optic must be adjustable to allow the beam to be centered on the optic.
Diamond™ GEM, G, & K, Integrator’s Guide Figure 7. Beam Delivery Components Attached Directly to Laser Collimated Laser Beam (See Beam Propagation Section) Figure 8. Laser Mount with Adjustments for Moving Axis Moving Laser When the laser itself is set on a moving axis, the beam delivery is generally fixed with respect to the laser. Beam delivery concerns, therefore, are the same as for a fixed beam.
Installation Collimated Laser Beam (See Beam Propagation Section) Figure 9. Laser and Additional Optics on Adjustable Mounting Plate The RF Cable RF cables have a finite life in terms of the number of bends they can withstand. As the bend radius is reduced, the life becomes shorter. Coherent provides cables with an extended flex life for use on systems with moving lasers. Even with these cables, it is good practice to do the following: • Use the shortest RF cable possible.
Diamond™ GEM, G, & K, Integrator’s Guide BEAM DELIVERY Many difficulties in laser processing systems arise from deficiencies in the beam delivery system. The beam delivery system has the vital job of transmitting the initially high-quality beam emitted by the laser to the workpiece without having the beam degraded by misalignment or aberrations. In addition, the beam delivery system must protect itself and the laser from light reflected from the processing region.
Beam Delivery in industrial environments is to have the beam path from the laser to the final focusing lens completely sealed, and purged with clean gas. Purge Gas Diamond K-series lasers have a purge gas inlet. The recommended gas is dry nitrogen, which is most conveniently obtained from a Dewar (nitrogen from cylinders, in addition to being more expensive than cryogenic nitrogen, is more subject to contamination with oil or water).
Diamond™ GEM, G, & K, Integrator’s Guide Where the beam path is fixed, aluminum tubing makes a good beam guard. It is available in many diameters and has a smooth outer surface that seals well. In most systems, beam guard tubes are black anodized although this has no effect on their performance. Mirages Nitrogen has a extremely small but finite absorption of 10.6 µm light. At high average laser powers, the gas in the beam delivery system will consequently be heated by the laser beam.
Beam Delivery Figure 10. Cross Section of Air Ejector for Protecting Bending Mirror one-way valves in the beam delivery system to allow excess purge gas to leave when the axes contract. For very high-speed systems, it may be necessary to have the purge gas flow switch from a normal rate to a higher rate when the axes extend. Polarization Diamond lasers have a highly polarized output. The direction of polarization is horizontal for all Diamond lasers but the K-400 and K-500, where it is vertical.
Diamond™ GEM, G, & K, Integrator’s Guide Figure 11. Installation Dimensions for Coherent CQE Module 0175-989-00 occur, back reflections alter the laser output and degrade the beam quality. In other cases, the returned light may be focused on beam delivery optics so that they are destroyed. It is essential for GEM-series laser systems used in high beam return (back reflection) modes, to have an optical isolator in the beam delivery system.
Beam Delivery isolators referred to are for operation at 10.6 µm. For operation at 9.4 µm use CQE part number 0175-989-01 and isolator part number 0175-990-01. Damage to the laser due to back reflection is not covered by warranty, so the system designer should protect against it. Figure 12.
Diamond™ GEM, G, & K, Integrator’s Guide BEAM PROPAGATION Optics Basics It is not the intent here to have an exhaustive discussion of optics theory and beam propagation. That information is readily available in optics and laser text books. The following basic optics information will be helpful when designing a beam delivery system. Beam Diameter The typical Coherent CO2 laser beam is very close to an ideal Gaussian beam profile where the peak intensity of the beam is at the center.
Beam Propagation M2 (M Squared) Factor The actual laser beams differ somewhat from the ideal Gaussian profile shown in Figure 13. To handle the handle the deviation from the ideal case, the factor M2 or K has been developed and is often quoted in laser specifications. For the ideal beam the M2 factor is 1 and the factor increases as the beam deviates more from ideal behavior. For a beam with an M2 factor of 1.2, the beam is actually √ 1.2 = 1.1 larger than an ideal Gaussian beam.
Diamond™ GEM, G, & K, Integrator’s Guide Focusing a Beam Most laser processing applications call for focusing the laser beam to a small spot so that the high power density can accomplish the desired work. This is true for applications involving cutting, drilling, scribing, welding, and others on a wide range of material. The typical question is what is the spot size that will be achieved for this application.
Beam Propagation optical design. The Rayleigh range is the difference in distance between the beam waist location and the point at which the beam is 1.4 times larger. 2 πD o Z r = -------------2 4λM The beam waist diameter can be for a focused beam in this issue but it could also be any other beam waist and the equation is still applicable. For the same focused beam in the previous example, the Rayleigh range or depth of focus is: Zr = (3.14 x(0.245 mm)2) /(4 x 0.0106 mm x 1.2) Zr = (0.188 mm2) /(0.
Diamond™ GEM, G, & K, Integrator’s Guide divided by the beam diameter for each lens greater than 10 to minimize effects of aberration. Also the same guidelines on acceptable clear apertures and beam diameters given above are still applicable On gantry based systems, the beam expander can be used to adjust focus at the work surface. This is accomplished by setting the final objective lens to exactly it’s back focal length (BFL) from the work surface (along the middle of the optical axis).
Interfacing GEM-Series Lasers to Systems INTERFACING DIAMOND GEM-SERIES LASERS TO SYSTEMS The GEM-series laser control is via the 15-pin D-type connector on the RF power supply. The exception is the GEM-30 where control is via the RJ-45 interface connector. The information that follows is a summary and more detailed information on interfacing the laser is contained in the respective operator’s manual. Interlocks External interlocks must often be connected to the GEM-series laser.
Diamond™ GEM, G, & K, Integrator’s Guide Table 5. Signal Interface Description and Connector Pinout for GEM-25/50/60/100/200 PIN NO. 1 FUNCTION DESCRIPTION RS-423 MODULATION Input signal (unbalanced) The RS-423 specification requires a driver capable of delivering a signal between 4 V and 6 V into a test load of 450 Ω.
Interfacing Diamond Lasers to Systems Table 6. Signal Interface Description and Connector Pinout for GEM-30 PIN NO. 1 SIGNAL DESCRIPTION RF Enable TTL logic input; 1=RF ON, 0=RF OFF; 1 kΩ impedance This input turns on the laser. See also Pin 7, Control Enable, below. 2 SWR OK TTL logic output; 1=SWR OK, 0=SWR Fault; IOH = -0.4 mA, IOL= 8 mA Output is asserted when DC supply current (IDD) is below max. value. 3 LASER OK TTL logic output; 1=LASER OK, 0=LASER Fault; IOH = -0.
Diamond™ GEM, G, & K, Integrator’s Guide INTERFACING DIAMOND G & K-SERIES LASERS TO SYSTEMS Diamond lasers have three types of interfaces. For OEM lasers, connection is made directly to the RF amplifier. Basic and Performance lasers have the Diamond Digital Interface and, optionally, may be connected through the remote control. The information that follows is a summary and more detailed information on interfacing the laser is contained in the respective operator’s manual.
Interfacing Diamond Lasers to Systems part of an interlock system. It can provide up 50 mA of current at 5 VDC and is on as soon as the AC power is applied. Note that if an over-current or over-voltage situation occurs, the DC supplied must have the AC input power turned off and then back on to reset the DC supply and also reset the +5 V logic voltage RF Power Supply Control of the laser is performed through the DB25 connector on the RF power supply.
Diamond™ GEM, G, & K, Integrator’s Guide warning message if this signal stays high more than 1 millisecond. The control should wait 100 milliseconds after modulation starts to monitor the forward power to allow transients to dissipate. Duty Cycle Limit (Pin 10+, Pin 23–) The duty cycle is the ratio of the pulse width to the pulse interval. Each model of the Diamond laser has a specified maximum duty cycle.
Interfacing Diamond Lasers to Systems on the Performance power supply). Interlock signals are accessed through the DB9 plug marked User on Basic lasers and Interlock on Performance lasers. The DDI provides many more inputs and outputs than the OEM interface. In addition to the enable and modulation signals, inputs are provided for shutter control, the aiming laser, turning the DC power supply on, clearing faults and selecting output signals.
Diamond™ GEM, G, & K, Integrator’s Guide as axis limit signals. In most cases, key switches and similar safety-related devices may be put across pins 8 and 9 of the User connector on the DDI. It is better to connect operator access doors to the shutter signal, since opening the User interlock shuts the laser down. Systems using OEM lasers must incorporate comparable interlock functionality.
Beam Propagation Characteristics BEAM PROPAGATION CHARACTERISTICS OF DIAMOND GEM-SERIES AND K-SERIES LASERS GEM, G, and K-Series Beam Propagation The following charts describe the beam propagation characteristics for the GEM-series, G-series, and K-series laser. In the following tables, the distance is referenced from the front end plate of the laser head. The tables show only beam diameters up to 1.0 inch (25 mm) clear aperture optics. Beam diameters that are larger are unsuitable for most applications.
Diamond™ GEM, G, & K, Integrator’s Guide Table 8. Beam Diameter (Inches) vs. Distance From Laser (Feet) DISTANCE FROM LASER (FEET) GEM 30/50 GEM 60/100 G50/100 K150 K250 K500 0 0.07 0.15 0.07 0.28 0.27 0.43 0.5 0.09 0.15 0.09 0.28 0.27 0.43 1.0 0.12 0.16 0.13 0.28 0.27 0.43 2.0 0.21 0.18 0.22 0.28 0.27 0.44 3.0 0.31 0.21 0.32 0.29 0.28 0.44 4.0 0.40 0.24 0.42 0.30 0.29 0.44 5.0 0.50 0.28 0.52 0.31 0.30 0.45 6.0 0.60 0.32 0.62 0.32 0.32 0.45 8.
Accessory Manufactures and Services ACCESSORY MANUFACTURES AND SERVICES Air filtration Balston, Inc. 260 Neck Road, Box 8223 Haverhill, MA 01835-0723 (800) 343-4048 fax (508) 374-7070 Beam delivery components Laser Mechanisms, Inc. 24730 Crestview Court Farmington Hills, MI 48335 (810) 474-9480 fax (810) 474-9277 Beam seals, way covers A and A Manufacturing Co. Inc. 2300 S.
Diamond™ GEM, G, & K, Integrator’s Guide Virginia KMP Corp. U.S.A.
Index INDEX A F Air filtration 45 Algaecide 17 Alignment 24 ANSI standards 4 ANSI B11.21 3, ANSI Z 136.
Diamond™ GEM, G, & K Laser Integrator’s Guide Power rating 13, Power supply DC 38 RF 39 Protective housing Pumping 26 Purge gas 25 Consultants 46 Interlocks 5, 8 Requirements 2 Workplace 4 Sealing 24 Seals Moving beams 26 Shutter 19, 40 System integrators 2 14 7 R Rayleigh range 32 Remote control Interface 41 Remote interlock connector Requirements DC power supply 16 Facility 16 Performance 5 Safety 2 Responsibilities 3 Compliance 3 RF cable 23 RF power supply 39 V 5, View optics 10 Viewports 10 VSWR
Diamond™ GEM, G, & K Laser Integrator’s Guide © Coherent, Inc. 11/2002, Printed in the U.S.A.
