Tunable microchip laser and laser system for ranging applications

A laser system comprising:

• a resonator having a first and an opposed second end;
• a gain element positioned in the resonator having a first surface and an opposed second surface, wherein the first surface of the gain element has a reflective coating at a lasing wavelength to form the first end of the resonator;
• an output coupling element having a first surface and an opposed second surface, one of the first or second surfaces having a partially reflective coating at the lasing wavelength to form the second end of the resonator;
• a tuning element arranged to vary an optical path length between the first and second end of the resonator;
• a semiconductor laser arranged to generate a pump beam directed into the gain element;
• a beam splitter arranged to split off a portion of an output beam of the resonator;
• a monitor arranged to intercept the split-off portion of the output beam so as to provide an electrical signal proportional to an optical power incident on the monitor;
• and
• a controller, wherein the electrical signal is input into the controller and the controller is arranged
• (i) to supply a modulation voltage to the tuning element to scan a frequency of the output beam,
• (ii) to supply an offset voltage to the tuning element to maintain single frequency operation of the laser system over the frequency scan of the output beam caused by application of the modulation voltage, and
• (iii) to vary a drive current to the semiconductor laser in a feed forward manner to improve an amplitude stability of the output beam.