I. INTRODUCTION The Nd3+:YAG laser shall be employed in the investigation of spectroscopic phenomena associated with biological, macroscopic, mesoscopic, and nanoscopic materials where ever a pulsed emission from 1064nm, 532nm and 266nm is needed. The Nd3+:YAG laser is housed in AET 3.220A. The beam is deemed reconfigurable and may propagate throughout the laboratory as necessary. The Nd3+:YAG laser is a class IV laser which emits a pulsed emission no greater than 1.5J with a beam diameter of approximately 2mm and a divergence no greater than 1.0 mrad. Available laser lines with this system are 1064nm, 532nm, and 266nm. This laser system is currently disabled indefinitely. II. USERS, COLLABORATORS, & SPECTATORS The Laboratory Administrator (LA) is the primary person in charge of day to day operation of the lab and coordinates both lab spaces second in command to Dr. Dhiraj Sardar. This individual is chosen by Dr. Sardar and is ultimately responsible for laser, chemical, and bio safety concerns and regulations such as experimental design approval, training (bio, chemical, and laser) approval, etc. and may also be the CLSO and the BSO simultaneously. The Chemical and Laser Safety Officer (CLSO) is appointed by Dr. Sardar and the LA to coordinate any and all chemical and laser safety concerns arising from reconfigurable experiments. This individual is a laser operator and is responsible for the training of authorized users and requests approval for authorized users from the LA and Dr. Sardar. The Bio-Safety Officer (BSO) is appointed by Dr. Sardar and the LA to coordinate any and all bio safety concerns arising from reconfigurable experiments. This individual is a laser operator and is capable of training authorized users with the approval from the LA and Dr. Sardar. Authorized users are those persons who have received Laser Safety Training (SA 465), have read the SOP, and signed an appendix indicating they have understand the instructions for the laser application. The user list appendix to this SOP can be updated as frequently as necessary. All laser operators (LO) are to be trained in depth by either the laboratory administrator or the CLSO upon completing any and all laser safety courses required by the UT system. Training involves a month long period of observation, followed by supervision of the trainee operating the laser system(s) following the specified operating protocols. It is the discretion of the laboratory administrator or CLSO to approve the trainee as a laser operator. This approval is conditional on signatures from the laboratory administrator, the CLSO, as well as Dr. Dhiraj Sardar. Upon obtaining the aforementioned signatures the trainee will then be classified as a laser operator. A scientific collaborator (SC) shall be defined as any external personnel relevant to any experiment being conducted at AET 3.220 or AET 3.228. Scientific collaborators may or may not have experience with laser equipment and as such required UT training (SA465) must be completed in order to operate any laser equipment. At this point it is up to the discretion of the LA, the CLSO, and Dr. Dhiraj Sardar whether the collaborator shall move on to, or bypass the required ‘hands on’ training necessary to operate any laser system housed in either lab space. SCs shall be allowed in AET 3.228B and AET 3.220A during laser operation after completing a debriefing on the hazards of laser radiation. Prior to entry SCs must don appropriate laser safety goggles depending on what hazardous wavelengths shall be present at that time. A spectator is a visitor who does not participate in the experiment. As such any spectator is not allowed in any laser radiation zone during laser operation (i.e. AET 3.228B and AET 3.220A). Spectators may apply for SC status with approval from Dr. Dhiraj Sardar, the LA, and the CLSO. III. NORMAL LASER OPERATION Procedures for powering on the laser unit are given in the user manual. Schematic procedures are as follows: First, the LO will seek approval from the LA, CLSO, and BSO to operate the laser and experiment. Once granted approval the LO will enable the sign which provides notification outside the laboratory that laser emission is present in the laser room. Next, the user will engage the interlock system and supply power to the power supply and place a beam dump in front of the laser output coupler. Finally, following the user manual procedures the LO will start emission of the laser at the lowest possible power. Any error codes and/or troubles with the unit shall be reported to the LA and the CLSO and the LO will shut down all power to the system until a solution can be reached. The LO would then begin these procedures from the beginning. This unit is designed for reconfigurable experiment and as such does not employ an enclosed housing for the beam. Therefore great care should be taken when operating this system. Beam alignment procedures are outlined below. The beam is emitted from the output coupler at 21 cm from the table surface. The beam may be raised or lowered using mirrors. Curtains shall enclose all table/areas being used for the experiment to prevent radiation from entering zones not necessary to the experiment. These matters shall be coordinated and scheduled by the LO, LA, CLSO, and BSO prior to the experiment. IV. EYEWEAR SECTION The eyewear worn for standard laser operation should provide an optical density (OD) of at least 4 at wavelengths of interest. The eyewear for alignment of the laser while the pump beams are exposed should additionally provide OD2 at the wavelengths of interest. Standard protective laser eyewear will be provided at the entrance to the laboratory. The eyewear provided for Ti:Sapphire has OD4 thru OD7 at 695-1064nm. The eyewear provided for Neodymium wavelengths has OD3 or OD7 at 514-532nm and 1054-1064nm. The eyewear provided for Argon ion wavelengths has OD3 to OD7 at 457-532nm. The eyewear provided for dye laser wavelengths has OD3 to OD7 at 337nm thru 900nm. All laser protective eyewear will be inspected twice a year and the results will be recorded in a log sheet attached at the end of this SOP. For a detailed list of available eyewear see appendix B. Eyewear shall be tested twice a year as follows. Eyewear will be tested for their respective lasers using the lines associating with those lasers. The goggles will be set up in a split beam path (50/50) terminating at a pair of power meters. The optical density can then be determined following Beer’s law upon measuring the attenuation in power relative to the initial power. This data will be recorded in a logbook. Any defective goggles will be cataloged and replaced V. ALIGNMENT HAZARD CONTROL Internal Alignments: Absolutely no internal alignments will be made on this laser system by the laser operator. Faulty internal optics shall be handled by the LA and/or the CLSO. External Beam Alignments: External alignments of propagating beams shall be made at the lowest possible power. For these visible wavelengths a small white business card or lens paper may be used to trace the beam path. Once the beam has been externally aligned only then may the laser operator increased power to the desired level. Any adjustments of the beam path will be made at the lowest power setting. Users shall follow all safety procedures in detail as given in SA465 (Laser safety) and will absolutely never put themselves in a position eye-level with any beam no matter what power is being used. Failure to comply with these standard safety procedures will result in a removal of such individual from laser operator status indefinitely. VI. LASER HAZARD CONTROL 1. 1. Door Interlocks: The Nd3+:YAG laser shall be interlock controlled both externally and internally. Currently the laser is disabled and non-operational. This LSO shall be updated at the time when the laser system is planned for use. 2. Window/Door Covers: All windows are covered with plastic blinds as well as a grey curtain to prevent radiation from leaking out as well as sunlight from leaking into the laser room. The door’s window will be covered with black aluminum sheeting to prevent laser light from exiting the laser room. 3. Warning Signs: During laser operation lighted signs outside of the laser room will be lit indicating laser radiation is present. When no laser in operating the lights will indicate no laser radiation is present. Additionally, information will be posted on the laboratory door visible from the hallway indicating the power output, type, and warning of lasers present within the lab. 4. Unauthorized Operation (Class 4): Unauthorized operation of any laser is prevented by strictly controlling access to any and all laser systems. It is the responsibility of the LA, CLSO, and BSO to prevent any unauthorized use of the laser systems. Additionally these persons are the only ones with access to laser interlock keys and the lab is constantly kept locked and secure 24 hours a day, seven days a week. 5. Invisible Laser Beam “ON” Indicator: The Nd3+:YAG laser has UV output capabilities and as such great care shall be used when dealing with such beams. The LO will be advised to operate and align all beams with the 2nd harmonic at 532nm. This laser also has NIR emission at 1064nm and therefore IR cards may be used to trace out the beam paths. 6. Emergency Cut-off Switch (Class 4): Several emergency cut-off devices are located inside and outside the lab. First a laser interlock emergency stop button exists next to the interlock box inside the laser lab. Second, a large contact switch is employed behind the laser unit inside the laser room which may be turned off in the event of any emergency. Third, outside the laser room in AET 3.220 there is an emergency stop button which is capable of disabling all power to the laser room. Finally outside of AET 3.220 is a breaker panel which allows another route of disabling power inside the laser room. All laboratory personnel will be made aware of, and trained in operating these devices. VII. CONTROL OF ADDITIONAL LCA HAZARDS Hazards present include the following: Use of cryogens: A closed cycle helium cryostat is used to cool samples to 8K. The laser shall never be set at a power high enough to damage this device. Use of compressed gases A tank of liquid nitrogen is kept inside the laser room. Curtains will conceal this item during laser operation Use of high voltage supplies Laser power supplies as well as detectors will be operating at high voltage/high amperage. Users will be trained to handle these devices carefully. Exposed beam path The beam path will be exposed as a reconfigurable experiment. As such alignment procedures and general laser safety practices will be enforced strictly. Use of beam focusing optics Lenses will be employed to focus laser beams down to micron sizes and therefore care must be used when focusing light so sharply. Use of harmonic genration: The Nd3+:YAG laser has 1st, 2nd, and 3rd harmonic generation capabilities and as such Los will be trained to handle these wavelength prior to the laser being scheduled for use. VIII. ASSOCIATED CHEMICAL HAZARD CONTROL Chemicals are typically kept outside of the laser room; however typical chemicals such as deionized water, ethanol, methanol, and acetone will be used frequently in the laser room. Due to the flammable nature of such chemicals during laser operation they will be removed from the area and only used outside of any radiation zone. Chemical waste will be kept in a chemical hood outside of the laser room as well as all other chemicals. IX. CONTROL OF EMERGENCIES & ABNORMAL SITUATIONS In the events of: 1. Breakdown of a high voltage system Call 911 if help is needed, shut off power at main circuit breaker, and report to the LA, and Dr. Dhiraj Sardar. 2. Laser burns to eyes and/or skin Call 911, shut laser system down, report to LCA Supervisor and to the RSO. 3. Laser coolant (water) accidentally discharged into the environment Shut laser system down, report to the LCA supervisor, and report to Campus Police (x4242) to have the discharge cleaned up. 4. Fire or other life-threatening emergency: Call 911, quickly evacuate from the LCA and pull the nearest fire alarm. . APPENDIX A: FLOOR PLAN DIAGRAM APPENDIX B: EYEWEAR SECTION The following eyewear shall be worn at all times during laser operation. The laser operators shall be trained in what eyewear to use with the respective laser being operated. SCs will be instructed with which eyewear to wear. Eyewear currently available in AET 3.220: Three pairs of green tinted goggles: 190nm – 450nm OD5 (Dye Laser) 860nm-1720nm OD3 (Ti:Sapphire) One pair of white framed goggles: 780nm-860nm OD4 Two pairs of blue tinted goggles (for HeNe laser operation): 632.8nm OD6 Three pairs of orange tinted goggles: 190nm-532nm OD7 (Argon Ion, Dye Laser) 10,600nm OD5 Two pairs of Nd:YAG specific goggles 1064nm >OD5 550nm >OD5 One pair of brown tinted goggles: 190nm -532nm OD3 (Argon Ion, Dye Laser) 800nm-864nm OD5 (Ti:Sapphire) 865-1064 OD7 (Ti:Sapphire) Eyewear currently available in AET 3.228: Two pairs of green tinted goggles: 190nm – 450nm OD5 (Dye Laser) 860nm-1720nm OD3 (Ti:Sapphire) One pair of blue tinted goggles (for HeNe laser operation): 632.8nm OD6 Two pairs of orange tinted goggles: 190nm-532nm OD7 (Argon Ion, Dye Laser) 10,600nm OD5 APPENDIX C: AUTHORIZED USERS Dhiraj K. Sardar Kelly L. Nash @00913946 Robert C. Dennis @00786431 Brian Yust @01134656 Madhab Pokhrel @01182985 Edward Khachatryan @01212459 Fred Barerra @00149749 Sreerenjini Chandrasekahran @00964657 Nathan Ray @00930533 Chris L. Mimun @00557302 X ___________________ X ___________________ X ___________________ X ___________________ X ___________________ X ___________________ X ___________________ X ___________________ X ___________________ X ___________________ In addition to personnel named above, authorized users of this laser include non-resident personnel whose fulfillment of laser safety training requirements is documented by attachment of evidence of their training to the relevant ESAF.