User Manual WaveMate Wavelength Meter
User Manual WaveMate Wavelength Meter 27650 SW 95th Ave. Wilsonville, OR 97070
WaveMate User Manual 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. This exception does not allow copies to be made for others, whether or not sold, but all the material purchased may be sold, given or loaned to another person. Under the law, copying includes translation into another language. Coherent and the Coherent Logo are registered trademarks of Coherent, Inc. WaveMate is a trademark of Coherent, Inc. Every effort has been made to ensure that the data given in this document is accurate. The information, figures, tables, specifications and schematics contained herein are subject to change without notice. Coherent makes no warranty or representation, either expressed or implied with respect to this document. In no event will Coherent be liable for any direct, indirect, special, incidental or consequential damages resulting from any defects in its documentation. In the U.S.: Technical Support Should you experience difficulties with your product, or need technical information, please visit our website: www.coherent.com. You can obtain additional support by either telephoning our Technical Support Hotline at 1.800.343.4912, or e-mailing our Support Team at support.instruments@coherent.com. Telephone coverage is available Monday through Friday (except U.S. holidays). If you call outside our office hours, your call will be taken by our answering system and will be returned when the office reopens. If there are technical difficulties with your product that cannot be resolved by support mechanisms outlined above, please e-mail or telephone Coherent Technical Support with a ii
description of the problem and the corrective steps attempted. When communicating with our Technical Support Department, via the web or telephone, the model and serial number of the product will be required by the Support Engineer responding to your request. Outside the U.S.: If you are located outside the U.S., visit our website for technical assistance, or telephone our local Service Representative. Representative phone numbers and addresses can be found on the Coherent website: www.coherent.com. Coherent provides web and telephone technical assistance as a service to its customers and assumes no liability thereby for any injury or damage that may occur contemporaneous with such services. These support services do not, under any circumstances, affect the terms of any warranty agreement between Coherent and the buyer. Operating a Coherent product with any of its interlocks defeated is always at the operator's risk. iii
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Table of Contents TABLE OF CONTENTS Preface... vii U.S. Export Control Laws Compliance... vii Publication Updates... vii Symbols Used in This Document... viii Safety...1 Description...3 General...3 Technical Description...4 Operation...7 Setup...8 Adjusting Intensity...9 Offset Correction...10 Menus...10 Average...11 Reading...13 Time...13 Offset...13 Shutter...14 Broadband Source Measurement...14 Δλ-Mode...15 Optional High-resolution Operation...15 Optional Analog Output Operation...16 RS-232 Interface...16 Command Structure...17 Warranty and Service Information...19 Warranty...19 Obtaining Service...21 Product Shipping Instructions...23 v
WaveMate User Manual Appendix A: Specifications...25 LIST OF TABLES 1. RS-232 Software Commands...17 2. Coherent Service Centers...22 3. Specifications...25 LIST OF FIGURES 1. Dual Photodiode Wavelength Sensor Structure...4 2. Spectral Response Curves of Photodiodes...5 3. WaveMate Sensor Head...8 4. WaveMate Console...8 5. Menu Block Diagram CW Operation...11 6. Menu Block Diagram Pulsed Operation...12 vi
Preface Preface This manual contains user information for the Wave- Mate wavelength meter. 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. In addition, shipments of certain components are regulated by the State Department under the International Traffic in Arms Regulations. The applicable restrictions vary depending on the specific product involved and its destination. In some cases, U.S. law requires that U.S. Government approval be obtained prior to resale, export or re-export of certain articles. When there is uncertainty about the obligations imposed by U.S. law, clarification should be obtained from Coherent or an appropriate U.S. Government agency. Publication Updates To view information that may have been added or changed since this publication went to print, connect to www.coherent.com. vii
WaveMate User Manual Symbols Used in This Document This symbol is intended to alert the operator to the presence of dangerous voltages associated with the product that may be of sufficient magnitude to constitute a risk of electrical shock. This symbol is intended to alert the operator to the presence of important operating and maintenance instructions. viii
Safety SAFETY Carefully review the following safety information to avoid personal injury and to prevent damage to this instrument or any sensor connected to it. The use and measuring of lasers is potentially dangerous. This instrument operates over wavelengths that include non-visible laser emissions. Proper laser operating practice in accordance with manufacturer recommendations is vital. Eyewear and other personal protective equipment must be used in accordance with applicable laws and regulations. If in doubt of correct operating procedures, consult the laser manufacturer and your laser safety officer. The equipment is not for use in critical medical environments. Use only the power cord specified for the meter. The grounding conductor of the cord must be connected to earth ground. 1
WaveMate User Manual Do not operate the meter if its panels are removed or any of the interior circuitry is exposed. Do not operate the meter in wet or damp conditions, or in an explosive atmosphere. Operate the meter only within the specified voltage range. Do not apply a voltage outside the specified range of the input connections. Do not operate the meter if there are suspected failures. Refer damaged units to qualified Coherent service personnel. 2
Description DESCRIPTION General WaveMate offers a low-cost, compact solution for wavelength measurement of pulsed and CW laser sources from 450 to 1,000 nm. WaveMate can be set up quickly and easily with no special optical interface. It is ideally suited for wavelength monitoring of tunable lasers and laser diode stability. WaveMate can measure wavelengths to 0.1 nm resolution (0.01 nm resolution optional) with ± 0.5 nm accuracy (± 1.0 nm pulsed) from single shot to continuous wave. Measurements are shown on a bright 8-digit display along with intensity readout and analog bar graph indication to insure optimum sensor signal level. WaveMate s microprocessor control unit provides menu-selectable functions, including 0λ wavelength display mode, measurement averaging, single pulse sample and hold, signal integration, and background zero offset calibration. All functions can be set for fully automatic operation to provide maximum ease of use and accuracy. WaveMate s unique detector head design incorporates a temperature-stabilized dual wavelength response sensor element with built in variable attenuator, AutoBlock background references shutter, and a background limiting alignment insensitive beam input port. WaveMate is calibrated at no less than 10 specific wavelength points to insure accuracy of the sensor wavelength response. 3
WaveMate User Manual For non-pulsed measurement applications, an economical CW-only version of the WaveMate is available. WaveMate comes standard with an RS-232 serial port, cable, and interface software. Standard ¼-20 and 6 mm tapped holes are provided for convenient mounting to standard optical mounts or posts. Technical Description Wavelength measurement is based on a single photosensor consisting of two stacked silicon photodiodes (Figure 1). The absorption characteristics of the first photodiode acts as a filter for the second photodiode. This results in the two photodiodes having different spectral response curves (Figure 2 on page 5). By comparing the output of the two photodiodes, an intensity-independent signal unique for the wavelength of the incident beam is obtained. WaveMate consists of a sensor head and a console for processing and display. The sensor head contains the photodiode, photo amplifiers, thermostat, and a variable neutral-density filter (Figure 3 on page 8). In the console, both signals are error corrected and the wavelength is then calculated and displayed on the LEWD display. Figure 4 on page 8 shows the front and rear panels of the console. Figure 1. Dual Photodiode Wavelength Sensor Structure 4
Description Figure 2. Spectral Response Curves of Photodiodes 5
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Operation OPERATION This section discusses the following topics: Setup (page 8) Adjusting intensity (page 9) Offset correction (page 10) Menus (page 10) Broadband source measurement (page 14) Δλ-Mode (page 15) Optional high-resolution operation (page 15) Optional analog output operation (page 16) RS-232 interface (page 16) 7
WaveMate User Manual Setup Connect the sensor head to the socket on the back panel of the console (Figure 4). Check the AC setting switch on the back of the console. AC switch must be set to the correct voltage for the unit to operate properly. Unit may be damaged if AC voltage setting is incorrect. Connect AC power to the console. Figure 3. WaveMate Sensor Head Figure 4. WaveMate Console 8
Operation Turn on unit using switch on the rear panel of console. WaveMate requires a 15-minute warm-up period before measurements can be made. The LED display will display WAIT 15m. The display will show remaining time in the warm-up period until complete. Then ADJUST is displayed and an automatic offset correction is made. (If the shutter is set to ON in the SHUT menu, the shutter in the head will close and the output of the photosensors will be measured with no input to provide offset values.) Note that the 15-minute warm-up can be bypassed by pressing SET button. This should only be done when unit must be shut down momentarily. If warm-up is bypassed when unit has not been properly warmed up, readings will be incorrect for a period of 15 minutes. Select operating mode (PULSE or CW) with the switch on the front of console (only on Pulse/CW version). Unit is now ready for operation. Align head with laser beam. Insure that power density is 75 W/cm 2 (10 mj/cm 2 ). Power/energy density in excess of this value may damage the input attenuator. Adjusting Intensity If the intensity of the light is too low, the display will show I=#####. If the intensity is too high, OVER- LOAD will be displayed. The intensity must be adjusted with the variable attenuator on the front of the sensor head until a wavelength value is shown on the display. Relative light intensity is displayed by the height of the pointer to the right of the least significant digit (4 levels of intensity are displayed). Stability and insensitivity to 9
WaveMate User Manual background light improves when the intensity is higher. Use the variable attenuator to adjust intensity so it is as high as possible for the most accurate measurement. Offset Correction Offset correction is done by closing a shutter in the sensor head and the output of the photosensors is measured with no input. The shutter is then opened and this value is used as an offset for subsequent measurements. Offset correction can be done manually at any time by pressing SET button on the front panel. Offset correction is done automatically every minute when the Offset Mode is set to ON (see Menus). To insure correct measurement, offset correction should be done every 15 minutes when unit is in non-automatic mode (see Menus next). Menus Measurement modes can be changed by pressing the FUNCTION button on the front panel (see menu structures in Figure 5 on page 11 and Figure 6 on page 12). The first time the FUNCTION button is pressed when in normal operation, the AVERAGE menu is displayed. Each time the FUNCTION button is pressed, the next menu is accessed in the order READING, MEASURING TIME, OFFSET, SHUTTER, and returns to normal operating mode (an offset adjustment is made automatically when returning to normal operation). To advance through the choices in each menu, press the SET button 10
Operation (while in the MENU). The following parameters are controlled via the mode menus. All set values are retained when unit is switched off. Figure 5. Menu Block Diagram CW Operation Average Controls the number of measurements averaged to arrive at displayed value. The display will show AV followed by 0001 to 0064, then AUTO. Advance through settings 11
WaveMate User Manual by pressing SET button. The displayed number (AV 00##) equals the number of measurements averaged to display value. When set to AUTO, the average number is adapted to the integration time for a useful refreshment rate of the display (approximately 3 cps). In PULSED mode, only AV 0001 and AV 0004 are available (CW/Pulse Model only). In READHOLD mode, only AV 0001 is available (CW/Pulse Model only). When desired setting is displayed, press FUNCTION to go to the next menu. Figure 6. Menu Block Diagram Pulsed Operation 12
Operation Reading Sets either continuous update of display as measurements are made or manual update only for next valid measurement after SET button is pressed. Display will show either READAUTO (continuous update) or READHOLD (manual update). Setting reading to manual will also place Offset in manual mode. Toggle between settings by pushing SET button. It is recommended that READAUTO setting be used for low rep rate pulsed lasers. When desired setting is displayed, press FUNCTION to go to next menu. Time Sets the measuring time (sensitivity) in msec. Display will show TIME00## or TIMEAUTO. Measuring time values of 4, 11, 30, 80, and AUTO are available. Advance through settings by pressing SET button. When AUTO is selected, measuring time is optimized to input light intensity. The measuring time parameters fixed at 0030 and cannot be adjusted in PULSED mode (CW/Pulse Model only). When desired setting is displayed, press FUNCTION to go to next menu. Offset Sets the offset correction to either automatic or manual. Display will show either ZEROMANL or ZEROAUTO. In automatic mode, offset correction is done once per minute. In manual mode, offset is done only when SET button is pressed. Toggle between settings by pushing SET button. When desired setting is displayed, press FUNCTION to go to next menu. Selecting ZEROAUTO will turn the shutter on if the shutter is off (see below). 13
WaveMate User Manual When in the manual mode, offset correction should be done every 15 minutes for accurate measurements. Shutter Sets internal shutter to ON or OFF. When on, internal shutter in sensor head is closed each time offset correction is made. When off, internal shutter is not used. Display will show SHUT ON or SHUT OFF. Turning shutter off also places Offset in manual mode. Toggle between settings by pushing SET button. When desired setting is displayed, press FUNCTION to go to next menu. When shutter is off, offset correction should be done every 15 minutes by blocking the source and pressing SET for accurate measurements. Broadband Source Measurement When the WaveMate is used with multi-line or broadband sources, some average intermediate wavelength (depending on the spectral intensity curve) is measured and displayed. Multi-line lasers or high levels of background light can distort measured values. For accurate measurements, high source intensities (in relation to the background light level) are recommended. Multi-line sources should be narrowed with filters as much as possible. 14
Operation Δλ-Mode Optional High-resolution Operation The λ-mode displays the measured wavelength as a deviation (delta) from a user-set reference wavelength. The λ-mode is activated in CW or Pulsed mode operation by pressing the SET button for approximately 3 seconds (or longer). Upon activation, the current wavelength reading in CW operation or the next valid pulsed wavelength reading in Pulsed operation is defined as the reference wavelength. Subsequent measurements are displayed as the deviation (delta) from the reference wavelength. In CW and Pulsed operation, the λ-mode resolution is 0.1 nm (or optionally 0.01 nm within ± 5 nm from the reference wavelength and 0.1 nm outside this range).to set a new reference wavelength, press the SET button again for approximately 3 seconds or longer and the current wavelength reading will be used as the new reference wavelength. To leave the λ-mode, press the FUNCTION button and the normal wavelength reading is displayed. An optional high resolution option for the WaveMate can provide a resolution of 0.01 nm in CW mode. The overall accuracy in this mode remains at ± 0.5 nm. The high-resolution operation is activated by pressing the FUNCTION button once. The AVERAGE menu will then be displayed. Press the SET button repeatedly until HIGH RES is displayed. Press the FUNC- TION button again to toggle to the next menu. Choose other menu settings as desired as previously described and return to the wavelength display by pressing the FUNCTION button several times. When the high resolution operation is active, an increased AVERAGE menu value of 128 and a measuring TIME of 11 are fixed for better measurement stability. 15
WaveMate User Manual Optional Analog Output Operation The Analog Out Interface option for the WaveMate wavelength meter provides an output voltage between 4.5 and 10.0V that is proportional to the measured wavelength. The voltage value at the output directly corresponds to the measured wavelength value: 6.328V corresponds to 632.8 nm. The analog output signal is available through the BNC connector ( analog out ) located on the rear panel of the WaveMate. As soon as there is a wavelength reading at the WaveMate display, the corresponding voltage value will be sent to the analog output via the BNC connector. If no wavelength is displayed, the voltage at the analog output corresponds to the last valid wavelength value. RS-232 Interface The WaveMate is equipped with an RS-232 interface for downloading wavelength measurements. Default settings: 9600 baud No parity 8 bits 1 stop bit The interface has two modes of operation: Continuous data output (factory setting) Single data output on request The selection of operation mode is done through RS-232 software commands, as explained under Command Structure below. 16
Operation Command Structure The commands shown in Table 1 consist of two ASCII characters which must be sent to the WaveMate via the RS-232 interface. The second character (, ) is used as a terminator. Using (0Ah) or (0Dh) can also provide termination. Table 1. RS-232 Software Commands COMMAND q x c DESCRIPTION The continuous output of measured wavelength data is stopped. A single wavelength measurement will be returned, consisting of the following ASCII characters (as would be seen for measurement of a HeNe laser at 632.8nm): 623.8nm2 followed by (0Ah) (0Dh) as terminators. The 2 behind the wavelength in the example corresponds to the second measurement range. (factory setting) Continuous output of measured wavelength data is started. The wavelength values will be transferred (as shown above) as often as they are measured without handshaking. 17
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Warranty and Service Information WARRANTY AND SERVICE INFORMATION This section includes information on the following topics: Warranty (this page) Obtaining service (page 21) Product shipping instructions (page 23) Warranty The seller warrants to the original Buyer each item manufactured by it to be free from defects in material and workmanship for a period of time and under such conditions as specified in the Seller s warranty for the individual product, or for twelve (12) months from delivery if a warranty for the individual product is not specified. Major sub-systems manufactured by other firms but integrated into the Seller s systems are covered by the original Manufacturer s warranty. The Seller s liability under valid warranty claims is limited to repair or replacement at the Seller s plant or the Buyer s location, all at the option of the Seller. THE FOREGOING WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES, WHETHER WRITTEN, ORAL OR IMPLIED AND SHALL BE THE BUYER S SOLE REMEDY AND THE SELLER S SOLE LIABILITY ON CONTRACT OR WARRANTY OR OTHERWISE FOR THE 19
WaveMate User Manual PRODUCT. THE SELLER DISCLAIMS ANY IMPLIED WARRANTY OR MERCHANTABILITY OR FITNESS FOR PURPOSE. All claims under warranty must be made promptly after occurrence of circumstances giving rise thereto, must be received within the applicable warranty period by the Seller, and shall be subject to the terms and conditions stated herein. Such claims should include the product serial number, the date of shipment, and a full description of the circumstances giving rise to the claim. Before any products are returned for repair and/or adjustment, authorization for the return and instructions as to how and where these Products should be shipped must be obtained from the Seller. Any product returned to the Seller for examination and/or warranty repair shall be sent prepaid via the means of transportation indicated as acceptable by the Seller. The Seller reserves the right to reject any warranty claim on any item that has been shipped by non-acceptable means of transportation. When any product is returned for examination and inspection, or for any other reason, the Buyer and its shipping agency shall be responsible for all damage resulting from improper packing or handling, and for loss in transit, notwithstanding any defect of non-conformity in the Product. In all cases, the Seller has sole responsibility for determining the cause and nature of failure, and the Seller s determination with regard thereto shall be final. If it is found the Seller s Product has been returned without cause and is still serviceable, the Buyer will be notified and the Product returned at the Buyer s expense. A charge for testing and examination may, in the Seller s sole discretion, be made on products so returned. 20
Warranty and Service Information Obtaining Service In order to obtain service under this warranty, Customer must notify the Company of the defect before the expiration of the warranty period and make suitable arrangements for the performance of service. The Company shall, in its sole discretion, determine whether to perform warranty service at the Customer's facility, at the Company's facility or at an authorized repair station. If Customer is directed by the Company to ship the product to the Company or a repair station, Customer shall package the product (to protect from damage during shipping) and ship it to the address specified by the Company, shipping prepaid. The customer shall pay the cost of shipping the Product back to the Customer in conjunction with annual recalibration and repair; the Company shall pay the cost of shipping the Product back to the Customer in conjunction with product failures within the first twelve months of time of sale or between annual recalibrations. A Returned Material Authorization number (RMA) assigned by the Company must be included on the outside of all shipping packages and containers. Items returned without an RMA number are subject to return to the sender. For the latest Customer Service information, refer to our website: www.coherent.com. Detailed instructions on how to prepare a product for shipping are shown under Product Shipping Instructions on page 23. 21
WaveMate User Manual Table 2. Coherent Service Centers LOCATION PHONE FAX E-MAIL USA 1.800.343.4912 503.454.5777 info_service@coherent.com Europe +49-6071-968-0 +49-6071-968-499 info_service@coherent.com International 503.454.5700 503.454.5777 info_service@coherent.com 22
Warranty and Service Information Product Shipping Instructions To prepare the product for shipping to Coherent: 1. Contact Coherent Customer Service (refer to Table 2 on page 22) for a Return Material Authorization number. 2. Attach a tag to the product that includes the name and address of the owner, the person to contact, the serial number, and the RMA number you received from Coherent Customer Service. 3. Wrap the product with polyethylene sheeting or equivalent material. 4. If the original packing material and carton are not available, obtain a corrugated cardboard shipping carton with inside dimensions that are at least 6 in. (15 cm) taller, wider, and deeper than the product. The shipping carton must be constructed of cardboard with a minimum of 375 lb. (170 kg) test strength. Cushion the instrument in the shipping carton with packing material or urethane foam on all sides between the carton and the product. Allow 3 in. (7.5 cm) on all sides, top, and bottom. 5. Seal the shipping carton with shipping tape or an industrial stapler. 6. Ship the product to: Coherent, Inc. 27650 SW 95th Ave. Wilsonville, OR 97070 Attn: RMA # (add the RMA number you received from Coherent Customer Service) 23
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Appendix A: Specifications APPENDIX A: SPECIFICATIONS Table 3 lists specifications for the WaveMate. PARAMETER Wavelength Range Accuracy Resolution Sensitivity Dynamic Range CW Operation Table 3. Specifications DESCRIPTION 450 to 1000 nm ± 0.5 nm (CW) ± 1.0 nm (pulsed) 0.1 nm (optional 0.01 nm) 20 µw (CW @ 633 nm) 10 µj (pulsed) 1000:1 with variable attenuator provided CW or lasers modulated @ > 5 khz Pulsed Operation Single shot to < 10 KHz fully automatic triggering (pulse widths > 100 f sec.) Damage Threshold (attenuator) 75 W/cm 2, 10 mj/cm 2 Warm-up Time Interface Input Port Diameter Power Supply Weight Mounting Post 15 minutes RS-232 serial port 4 mm 120V/60 Hz, 240V/50 Hz, rear panel selectable, fused 200/100 ma Sensor head: 1.26 lb. (0.56 kg) Control unit: 3.14 lb. (1.41 kg) ¼-20 and 6 mm thread on center 25
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WaveMate User Manual Coherent, Inc., 3/2009. Printed in the U.S.A. Part No. 0214-900-00, Rev. CA