Spot Series Lasers
Contents
1. 1 6 Operation with power variation 2 User Guide SPOT Power Supply 2 1 Front Panel 2 2 Rear panel 2 3 RS232 commands SPOT Manual docx 3 08 08 2014 1 1 System Description The SPOT laser systems consist of a laser head with a separate power supply unit The power supply unit contains the drive circuits for the pump laser diode and the temperature control of the laser system as well as the DC supplies for these modules and to supply the HV for the Pockels Cell There is an interconnecting cable from the laser head which is hard wired into the laser head while having a 37 way D connector for connection to the power supply unit The power supply requires a mains input of 100 240 VAC 50 or 60 Hz capable of providing up to 200VA SPOT lasers are designed to generate short pulses of laser output at 1064nm and harmonics if specified The output power level will depend on the model but it should be remembered that all SPOT lasers emit laser radiation which is potentially hazardous and itis therefore strongly recommended that before operating the laser for the first time users should thoroughly familiarise with the contents of this manual Of particular importance are the sections dealing with safe operation of the laser and general safety issues Please refer to Section 2 for full details of power supply operation Q switch voltage adjustment with repetition rate With variation of repetition rate up to 50 kHz it is nece2. TO INADEQUATE HEATSINKING MAY INVALIDATE ANY WARRANTY SPOT Manual docx 7 08 08 2014 1 5 Basic Operation The SPOT series Diode Pumped Laser Systems are designed for simple user friendly control with the minimum of user defined parameters SPOT lasers are designed as fixed power level devices under automatic operation or power can be varied by adjusting the pump diode current via RS232 interface The power drawn from the AC mains is less than 200 VA typically approx 50 VA The laser head incorporates laser diode protection circuitry and therefore the laser diode is protected even when disconnected from the laser power supply However Elforlight recommend the observance of full anti static precautions during connection and disconnection of the system sub units Please contact Elforlight for recommended anti static procedures Connect the laser head to the power supply unit using the 37 way D connector socket on the rear of the power supply Be sure that the cable is kept away from the laser beam path Ensure the external interlock connector is in place in the socket on the PSU rear panel Ensure that the external interlock circuit is closed either by use of the supplied shorted connector temporarily for test only or via a user supplied door or enclosure protection circuit This interlock should be incorporated into an area or enclosure interlock system Please contact Elforlight for advice regarding suitable interlock arrangeme
3. by the front panel switch SPOT Manual docx 13 08 08 2014 2 3 SPOT Laser RS232 Commands Allows User to change laser diode current Iset and thus laser power Increment Iset parameter by one Decrement Iset parameter by one Request status Q Request software version number RS232 protocol 9600 baud 1 start bit 8 data bits no parity 1 stop bit No hardware handshaking No software handshaking RS232 Cable wiring PC End Laser End 9 way 9 way D type D type Socket Plug 4 6 7 8 SPOT Manual docx 14 08 08 2014
4. ELFORLIGHT Spot Series Lasers Short Pulse Optical Technology Elforlight Ltd 4B Brunel Close Drayton Fields Daventry Northants NN11 8RB UK Tel 44 1327 300069 Fax 44 1327 300076 www elforlight com SPOT Manual docx 1 08 08 2014 NOTICE Efforlight Ltd has made every attempt to ensure that the information in this document is accurate and complete Elforlight Ltd assumes no liability for errors or for any incidental consequential indirect or special damages including without limitation loss of use delays or lost profits or savings arising from the use of this document or the product which it accompanies The contents of this manual are subject to change without notice Please contact the factory to ensure you have the latest revision of this document before embarking on critical design No part of this document may be reproduced or transmitted in any form or by means electronic or mechanical for any purpose without written permission from Elforlight Ltd Elforlight Ltd acknowledges the trademarks of other organizations for their respective products or services mentioned in this document 2011 Efforlight Ltd All rights reserved SPOT Manual docx 2 08 08 2014 Contents 1 Basic User Manual 1 1 System Description 1 2 Laser safety 1 3 Recommended safety precautions during laser operation 1 4 System handling mounting and heat sinking 1 5 Basic Operation Connections Start up procedure
5. TION OF THE EQUIPMENT DUE TO EXCESSIVE FORCE MAY INVALIDATE ANY WARRANTY All SPOT lasers are supplied with a mounting block base for the laser head This is usually already attached to the laser head as shipped The laser head produces a maximum of 15W waste heat and any installation should be designed with this in mind The mounting block incorporates four M6 counter bored clearance holes suitable for bolting the block to an optical table or other mounting surface If it is not possible to include the mounting block within the installation the laser can be mounted directly to a suitable surface provided that the heatsinking requirements are met Mounting the laser head without the base The laser head is attached to the base by 3 off M2 5X10 screws If the head is to be attached directly to another surface the maximum thread depth allowed into the laser head is 5mm On no account exceed this depth It is recommended that a piece of either lead or indium foil is used to cover the surface area of the underside of the laser head as an interface between the head and the mounting surface N B THE MOUNTING BLOCK IN ISOLATION IS NOT INTENDED TO PROVIDE THE REQUISITE HEATSINKING THE BLOCK MUST STILL BE FIRMLY ATTACHED TOA SURFACE CAPABLE OF PROVIDING GOOD THERMAL TRANSFER ELFORLIGHT WILL WILLINGLY PROVIDE ANY ADVICE REQUIRED REGARDING CORRECT MOUNTING PROCEDURES AND THERMAL TRANSFER ANY DAMAGE OR MALFUNCTION OF THE EQUIPMENT DUE
6. e open loop and power ramp operation phase the laser output power will vary significantly from the specified output power This behaviour is quite normal as during this period optical stabilisation is occurring Once the laser is running monitor the output pulse shape with a photodiode and oscilloscope The HV adjust if fitted potentiometer can then be fine tuned for best stability and minimum pulse width This setting will vary with drive level and repetition rate SPOT Manual docx 9 08 08 2014 1 6 Operation with power variation Power variation is possible by RS 232 interface with commands sent from a dumb terminal The programs Terminal and or HyperTerminal are provided with Windows software and can be used The program should be configured with the parameters listed below 9600 baud 1 start bit 8 data bits no parity and 1 stop bit No hardware handshaking No flow control To operate the laser using power variation by RS 232 interface first boot the computer run Terminal Then connect the RS232 lead and power up the laser as described above An introductory message appears confirming PSU SEEPROMs detected Head SEEPROM not detected is normal and not a fault Digipots 1 amp 2 detected and listing SPOT software version e g V213 Turn the key A message Warm up confirms that a 5 minute warm up period is in progress followed by I ramp and I dwell then after 2 minutes Ready confirms
7. e of repetition rates See test data for settings 4 TTL Control Switch This 5 position switch allows the user to select internal or external triggering and to trigger internally at frequencies of 1 5 10 or 25 kHz Emission Indicator TTL Control Key Switch High voltage adjust if fitted SPOT Manual docx 12 08 08 2014 2 2 Rear panel 1 Mains inlet The mains inlet is a standard IEC connector A suitable mains cable is usually supplied with the laser as appropriate to the local supply The mains inlet is fused and switched Fuse rating is 5 Amps slow blow T 2 RS232 cable Connects laser PSU to serial COM port of computer Computer runs dumb terminal program such as Terminal or Hyperterminal PSU end is a round 5 way DIN connector 3 External Interlock connector A 3 way Neutrik connector Contact closure between pins 1 and 3 is required to enable laser operation Laser is supplied with a connector with a shorting link in place 4 Laser head 37 way D connector Provides laser diode drive current temperature control and monitoring of laser functions THIS CONNECTOR SHOULD NEVER BE CONNECTED OR DISCONNECTED WHILST THE LASER SYSTEM IS POWERED UP 5 Safety fuse for laser head Carries 5V supply to laser head Fuse rating is 1 25A slow blow T 6 Trigger out connector This BNC connector provides TTL trigger output to be taken to the laser head Trigger BNC for internal triggering at the frequency selected
8. lass 3B Only trained personnel should be allowed to use the laser The key must be inserted in the keyswitch and turned to enable the laser to operate The key is captive in the operational position As such the key should be removed from the laser when not in use and or unattended and stored in a safe place Eye and skin exposure to direct or scattered laser radiation is hazardous and should be considered potentially extremely harmful Suitable eye protection should be worn at all times whilst laser output is possible Contact Elforlight for advice on suitable eye protection products The laser beam path should be terminated with a non reflecting beam stop Beam paths should be enclosed where possible and should not be at eye level if practical Care should be taken that all mirrors and optics used are securely positioned and fixed to prevent movement Care should be taken at all times to prevent stray reflections from surfaces in the beam path SPOT Manual docx 6 08 08 2014 1 4 System Handling Mounting and Heatsinking It must be appreciated that any solid state laser system especially the laser head is a sensitive piece of scientific equipment Whilst every effort has been made to provide a product that is rugged and reliable it is essential that the laser head is handled with care especially when mounting Do not drop or subject the head to impact shock such as placing it down hard on a surface ANY DAMAGE OR MALFUNC
9. nts Either connect a user supplied TTL trigger signal to the Trigger BNC connector on the laser head or connect a BNC cable from the PSU rear panel trigger out BNC connector to the laser head Trigger BNC to run on the internal trigger In the latter case select the desired operating frequency using the front panel switch 1 5 10 or 25 kHz Connect the mains cable to the rear panel socket Apply power switch on the rear panel rocker switch integral with the mains inlet and turn the key switch to the ON position Operation The SPOT laser executes a start up procedure during which the output power will vary During this sequence the front panel LED emission indicator flashes at 0 5 Hz Only when the LED is on continuously is the power locked at specified power and the laser ready for use Before this lower or higher powers may be observed from the laser The SPOT laser exhibits two different start up sequences depending on the length of time the unit has been connected to the mains supply These may be described as 1 Cold start sequence 2 Warm start sequence 1 The cold start sequence is activated when the system has been powered down and is subsequently reconnected to the mains supply that is on initial start up 1 1 Connect power supply to mains supply and switch ON Insert keyswitch and turn ON SPOT Manual docx 8 08 08 2014 The cold start sequence now begins with a thermal stabilisation period F
10. rom power up this phase takes a total of 4 minutes During this period no laser output will be generated irrespective of whether the key switch is in the OFF anticlockwise or ON clockwise position The keyswitch may be switched ON at any time during this 4 minute period without prolonging the next stage of start up After the above 4 minute warm up period the supply switches automatically to an open loop control mode which lasts 1 minute During this period some laser light may or may not be emitted depending on the individual set up parameters of the laser After the above 1 minute open loop period the laser output is ramped up from a low value to full output after which it remains in a power locked mode The total time for this power ramp is dependent upon the specific power level set At the end of this period the Emission indicator will remain permanently on The warm start sequence is activated any time the key switch is moved from the OFF position to the ON position provided the system has been powered up for at least 4 minutes The warm start sequence activates the final two periods as in 1 above that is the open loop period and the power ramp period NOTE 1 if the system is powered down even momentarily at any time or the interlock broken when the system is powered up subsequently the system will automatically revert to the cold start sequence NOTE 2 During th
11. ser s responsibility to ensure full compliance with these standards Emission The laser emits CW or pulsed radiation at 1064nm 532nm and 355nm or as otherwise specified Powers up to 2Watts may be generated The laser head also contains a laser diode emitting radiation at 808 nm within the head package THE LASER HEAD COVER MUST NOT BE REMOVED No customer serviceable parts are contained therein Such access may invalidate any warranty offered by the manufacturer Indicators An emission indicator on the front panel of the power supply indicates that laser emission is possible External interlock The SPOT series laser systems are provided with an external interlock facility which is available on a Neutrik 3 way socket on the rear panel This connector requires contact closure to enable laser operation The laser is supplied with a shorted connector but it is recommended that the short be replaced by a link into an external interlock chain e g a room door switch or enclosure cover switch Ifthe interlock is broken it is necessary to power down the laser at the keyswitch then remake the interlock connection and commence the start sequence again to resume laser output SPOT Manual docx 5 08 08 2014 1 3 Recommended Safety Precaution during Laser Operation The laser should be used in an enclosed area with access restricted to trained personnel The area should be clearly labelled and the entrance marked with the class of laser C
12. ssary to adjust the high voltage applied to the Q switch to optimise output in terms of pulse width and stability This can be done by monitoring the output pulse on a photodiode and oscilloscope whilst adjusting the voltage using the 10 turn potentiometer if fitted on the front panel Voltage values are given in the test data table above for various repetition rates The potentiometer if fitted can be locked by sliding the plastic lever to the right and unlocked by sliding it to the left SPOT Manual docx 4 08 08 2014 1 2 Laser Safety This handbook contains a description of controls adjustments and procedures for normal operation of the laser CAUTION Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure Classification Elforlight SPOT series lasers are classified as class 4 Lasers as defined by BS EN 60825 1 1994 and by the United States Centre for Device and Radiological Health CDRH 21 CFR Ch 1 subsection 1040 This designates potential danger of eye or skin damage by exposure to direct or scattered radiation It is recommended that all users should thoroughly familiarise themselves with these safety standards before operating the laser for the first time It should be noted the all SPOT lasers are designed as OEM sub systems As such they do not comply with all the requirements of BSEN 60825 1 1994 and CDRH 21 CFR Ch 1 subsection1040 It is the u
13. the laser is operating During this start up phase the emission LED flashes Once ready the emission LED is on solid The and keys can then be used to increase and decrease the pump diode current and hence laser power The current is set by an 8 bit Digipot with values 1 to 254 being accepted Do not exceed 254 Ateach key press the value xxx is returned xxx is the value between 1 to 254 See test data for calibration of values with current and corresponding power output SPOT Manual docx 10 08 08 2014 2 SPOT Power Supply The SPOT supply also contains An OEM 18 04 Controller A triple rail DC supply for the above A 5V DC supply for the high voltage switch in the HV module A further adjustable DC supply to drive the high voltage supply in the HV module A cooling fan Interconnecting wiring to bring limited functionality of the 18 04 supply to the front panel The SPOT laser software is limited in functionality It enables the user to vary laser power by varying pump diode current and to check the laser status SPOT Manual docx 11 08 08 2014 2 1 Front panel 1 Emission indicator A yellow LED Flashes during warm up continuously illuminated when lasing possible 2 Key switch The key switch enables laser output See discussion of start up sequence for details 3 HV adjust potentiometer if fitted Adjusts the high voltage applied to the Pockels Cell to allow operation over a wide rang
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