Investigation of controlled external feedback on the properties of low and high-power frequency-stabilized diode laser

Abstract

Unwanted optical feedback is a common problem in many optical setups of laser systems. To quantify the effect, the influence of a controlled external feedback on the emission properties of a low power distributed feedback ridge waveguide and a high power distributed Bragg reflector tapered diode laser are analyzed. The measured influence of the phase dependent feedback over several orders of magnitude in feedback power attenuation on emission wavelength is discussed and compared to theory.

Hybrid semiconductor master-oscillator power-amplifiers with more than 5 W optical output power

“…second harmonic generation (SHG) was sufficient to alter the entire emission spectrum of the laser making the SHG unstable [23,24]. It was shown that feedback ratios as small as -60 dB can have a significant impact on the spectral properties of DBR-TPLs [25]. Periodically poled crystals create feedback of the order of -50 dB to -30 dB [24].…”