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Passively Q Switched Laser
Navy SBIR FY2015.2
| Sol No.: |
Navy SBIR FY2015.2 |
| Topic No.: |
N152-089 |
| Topic Title: |
Passively Q Switched Laser |
| Proposal No.: |
N152-089-0355 |
| Firm: |
Scientific Applications & Research Assoc., Inc.
6300 Gateway Dr.
Cypress, California 90630 |
| Contact: |
Nathan Zameroski |
| Phone: |
(719) 302-3117 |
| Web Site: |
http://www.sara.com |
| Abstract: |
Scientific Applications and Research Associations (SARA) proposes an R&D program to develop a passively Q-switched Tm:YLF laser using Cr:Zn:Se, Cr:Zn:S, Co:Zn:S, or Co:Zn:S as the solid state saturable absorber. Passive Q-switching reduces cost, weight, volume, eliminates bulky electro-optical active Q-switches and associated electronics, and simplifies resonator design. Passively Q-switched lasers are compact, ruggedized, reliable, packaged to withstand the shock, vibration, pressure, temperature changes, and have nearly diffraction limited beams. The gain crystal, Q-switch, and resonator mirrors can be integrated onto a monolithic device. High average power (>11 W) passively Q-switched Nd:YVO4 lasers using Cr+4:YAG saturable absorber have been demonstrated but pulse energy and repetition rate were ~ 60 ?J at 190 kHz because of the fast 4 ?s lifetime of the saturated transition in Cr+4:YAG. However, both Co:Zn:S, and Co:Zn:Se have saturated transition lifetimes ~ 200 to 300 ?s at 295 K and lifetimes increase to ~ 600 to 800 ?s at 250 K. This may permit temperature tuning of repetition rate and open up the possibility to CW pumped, high energy (mJ range), high average power passive Q-switching at sub-kHz repetition rates. Benefits of funding include publishing research and commercial applications such as laser scalpels, LIDAR, and pollution monitoring. |
| Benefits: |
Phase I, if successful would provide an opportunity to publish in peer reviewed journals and also present at conferences. Furthermore it would further establish SARA�s directed energy portfolio beyond high power microwave and high power laser diagnostics instrumentation to laser systems and remote sensing capabilities. SARA�s commercialization strategy for a passively Q-switched Tm:YLF laser would focus on both defense and commercial applications. Since the emission wavelength of Tm falls in the eye safe wavelength region of the electromagnetic spectrum and its 4th harmonic falls in the water transmission window, Tm lasers may find use in remote sensing (earth and space based LIDAR) and direct optical communications in both air and water. Furthermore, Tm lasers may be used for �infrared counter measures to defeat shoulder-launched infrared �heat seeking� missiles that pose a threat to slow moving aircraft such as helicopters and civilian airplanes� [ ]. Another promising application focus is the medical device field. The penetration depth (1/e) of ~1900 nm radiation in water is only ~ 500 ?m to 1 mm. Since biological tissue is mostly comprised of water, Tm lasers may be exceptional tools for precise cutting of tissue [ ], i.e. laser scalpels. Other medical uses include, dentistry, gallstone removal, eye surgery, and coronary angioplasty [i]. Finally, other promising applications of Tm lasers are in materials processing and plastic welding, spectroscopy, and pollution monitoring. SARA has identified 4 market areas where the key technologies developed under this program could be brought to bear. They are: 1) Surgical lasers. The market for lasers used for surgical applications is currently valued at $745M and growing at a 13% year-over-year growth rate. The Thulium wavelength (1.9 ?m) is preferred for haemostatic cutting of soft and hard tissue. The flexibility of the Thulium wavelength enables deployment into a large variety of applications: urology, gastroenterology, thoracic and pulmoneary, gynecology, ENT, dermatology, arthroscopy, and general surgery. 2) Material processing. The market for lasers for material processing tops $3.8B. Within this large market are various sub-markets. The 1.9 ?m wavelength is particularly well suited for welding clear polymer pieces together. In particular, this wavelength is used exclusively for welding of clear polymer medical device components. In medical device manufacturing, clear polymer is the material of choice � due in large part as it enables the inspection of devices for integrity, cleanliness, and functionality. 3) LIDAR. LIDAR (which includes airborne LiDAR, terrestrial LiDAR, mobile LiDAR, and short-range LiDAR) is expected to enjoy a 16% annual growth rate, reaching a $1B for devices and systems in 2020 [ ]. 1.9 ?m to 2.0 ?m lasers are used for long range and atmospheric detection. LIDAR is a niche market with low volume/high mix production features. This market may be addressable through internal manufacturing capability. 4) Pollution monitoring. This $3B market for air pollution monitoring, sampling, and process control [ ] is generally served through niche manufacturers with strong relationships to the factories and power plants. O2, H2O, CO, CO2, NO, NO2, OH, NH3, HF, H2S, and CH4 are typical �emissions� and are well-resolved with interrogation by 2 ?m laser light. There is a need for the plant to monitor to ensure compliance as well as for regulators to confirm compliance. As air pollution regulations increase, the need for monitoring increases as well. _________________________ . i. �High-power diode lasers operating at 1800-2100-nm for LADAR and direct use in IRCM applications� white paper from nlight ii. Pavel Cerny and Helena Jelinkova, �Developing thulium lasers for depth-selective scalpels�, SPIE Newsroom, 10.1117/2.1200607.0281 iii. North America LiDAR Market By Product Type, By Application, and By Geography - Analysis and Forecast (2014-2019) http://www.giiresearch.com/report/mmm330471-north-america-lidar-market-by-product-type.html iv. McIlvaine Air Pollution Monitoring and Sampling World Markets. http://www.environmental-expert.com/news/3-billion-market-for-air-pollution-monitoring-sampling-and-process-control-223284 |
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