Compact ps light source for materials analytics and materials processing
The ps light source combines laser and high frequency know-how of the FBH
At FBH, a novel ps light source has been developed consisting of a mode-locked diode laser with hybrid-integrated pulse picker and amplifier. The laser source utilizes optimized components from the institute’s diode laser and high frequency GaN technology – all elements base on FBH’s core competencies.
The optical components as well as the high frequency electronics are mounted on a micro bench with a footprint of 5 x 4 cm2 (see Fig.). A 1 cm long monolithically integrated 4-section DBR laser is used as master oscillator generating ultra-short light pulses by mode locking with a full width at half maximum of 10 ps and a repetition rate of ~4,3 GHz (230 ps pulse spacing). The optoelectronic device with high frequency-gated RW waveguide and pulsed tapered amplifier) consists of two sections and is used for pulse selection and amplification. Coupling between these devices and beam shaping behind the tapered amplifier is executed by means of micro-optical lenses. All parts are adjusted and fixed to each other with highest precision. The compact setup results in a highly stable assembly. For electronic excitation, FBH uses in-house developed ultra-fast GaN transistors with low capacitance and high current density. Specifically challenging for the picking of single pulses is to switch the current pulses on and off within 100 ps.
With this laser source from the FBH, a compact module has been developed providing ultra-short light pulses <10 ps with a selectable repetition rate from the Hz up to the GHz range. Applications for the capable and highly flexible laser source are especially in materials analytics and materials processing. It can be used, for example, as flexible seed source for fiber and solid-state laser amplifiers.
Publications:
"<link /fileadmin/fbh-berlin/english/ver10/pub36.htm _blank internal-url-new-window>Laser Driver Switching 20 A with 2 ns Pulse Width Using GaN", A. Liero, A. Klehr, S. Schwertfeger, T. Hoffmann, W. Heinrich, Proc. IMS 2010, Anaheim,USA, may 25-27, pp1110.
"<link /fileadmin/fbh-berlin/english/ver11/pub36.htm _blank internal-url-new-window>Compact ps-pulse laser source with free adjustable repetition rate and nJ pulse energy on microbench", A. Klehr, A. Liero, Th. Hoffmann, S. Schwertfeger, H. Wenzel, G. Erbert, W. Heinrich and G. Tränkle, Novel In-Plane Semiconductor Lasers X, edited by Alexey A. Belyanin, Peter M. Smowton, Proc. of SPIE Vol. 7953, 79531D · © 2011 SPIE · CCC code: 0277-786X/11.
FBH research: 10.11.2011