High power density as the critical performance of laser diode pumps significantly affects both efficiency and power of a solid state laser. In this report, we designed a new packaging structure that two laser bars bonded on the top and bottom of a MCC, respectively, to achieve higher power density at the same bias current or the same power density at a reduced bias current with respective to one laser bar on a MCC. We achieve 1KW output power at a lower bias current 450A with 2.3W/A slope efficiency from a dual-bar MCC at a duty cycle of 8% (200 μs/400 Hz). Other performances like spectral width broadening, wavelength shift and reliability about 1KW quasi-CW high power laser diodes and 5KW for one vertical stack with five dual-bar micro-channel coolers (MCCs) also are discussed. The reliability of dual-bar MCC packaging structure is also studied by life-time testing, and the output peak power of all devices degraded less than 5% after working for 1353 hours.
KEYWORDS: Semiconductor lasers, Copper, Reliability, Continuous wave operation, Corrosion, High power lasers, Laser development, High power diode lasers, Ceramics, Resistance
An insulation micro-channel cooling (IMCC) has been developed for packaging high power bar-based vertical stack and horizontal array diode lasers, which eliminates many issues caused in its congener packaged by commercial copper formed micro-channel cooler(MCC), such as coefficient of thermal expansion (CTE) mismatch between cooler and diode laser bar, high coolant quality requirement (DI water) and channel corrosion and electro-corrosion induced by DI water if the DI-water quality is not well maintained The IMCC cooler separates water flow route and electrical route, which allows tap-water as coolant without electro-corrosion and therefore prolongs cooler lifetime dramatically and escalated the reliability of these diode lasers. The thickness of ceramic and copper in an IMCC cooler is well designed to minimize the CTE mismatch between laser bar and cooler, consequently, a very low "SMILE" of the laser bar can be achieved for small fast axis divergence after collimation. In additional, gold-tin hard solder bonding technology was also developed to minimize the risk of solder electromigration at high current density and thermal fatigue under hard-pulse operation mode. Testing results of IMCC packaged diode lasers are presented in this report.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.