Picosecond pulses with more than 60 W peak power generated by a singlestage all-semiconductor master-oscillator power-amplifier system

Abstract

In this contribution the authors report a different operation of a DBR laser diode which allows the generation of laser pulses with a length of 65 ps and a very high peak power. Laser pulses are generated by injecting less than 1 ns long electrical pulses with a peak current of several amperes into the gain section, whereas the DBR and absorber sections are shorted or reversed biased. The pulsed operation of the gain section minimizes the self heating of the laser. The electrical pulses are provided by an emitter-coupled logic (ECL) electrical circuit with a GaN based power stage described in the paper. The DBR section and the saturable absorber section are each 1 mm long. The total length of the cavity is 4 mm. The coupling coefficient of the grating in the DBR section is about 10 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> which results in an effective reflectivity of about 60%. Both facets are anti-reflection coated (R <; 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> ).