Miniaturized semiconductor MOPA laser source at 772 nm for the generation of UV laser light open site


Date: Feb 23, 2018
Miniaturized semiconductor MOPA laser source at 772 nm for the generation of UV laser light

For several fields such as spectroscopy, metrology, and lithography, laser sources in the ultraviolet (UV @ 386 nm) or deep ultraviolet (DUV @ 193 nm) spectral range rely on broad band or pulsed laser systems such as excimer lasers. Highly brilliant semiconductor laser systems could advance these fields further as they are more reliable and easier to handle.
One way to achieve the UV emission is using a 772 nm emitting semiconductor master oscillator - power amplifier (MOPA) laser system whose emission is frequency doubled once or twice in a later step. The laser system will be built into a small and compact package and consists of a MO, which is a distributed feedback (DFB) ridge waveguide (RW) laser. The diffraction limited laser emission with a single spectral mode is coupled into the PA for the amplification of the output power up to 3 W. The PA is a semiconductor laser with a RW and a tapered section. Optical feedback can be minimized by using a micro-optical isolator, which is placed between MO and PA that allows a linewidth of < 3 MHz.
We will present further experimental results of the MOPA system in detail. This includes the emission characteristics, the spectral emission behavior, and the robust setup by applying several thermal cycles and shaking tests.
On the base of the same laser system, wavelengths of 780 nm or 785 nm could facilitate small rubidium atomic clocks or Raman spectroscopy respectively. Especially when using distributed Bragg reflector laser diodes an even smaller linewidth can be achieved.