Antireflection Coated Semiconductor Laser Amplifier

This paper presents a laser amplifier based on an antireflection coated laser diode. This laser amplifier operates without active temperature stabilisation at any wavelength within its gain profile without restrictions on the injection current. Using a active feedback from an external detector to the laser current the power stabilized to better than $10^{-4}$, even after additional optical elements such as an optical fiber and/or a polarization cleaner. This power can also be modulated and tuned arbitrarily. In the absence of the seeding light, the laser amplifier does not lase, thus resulting in an extremely simple setup, which requires neither an external Fabry Perot cavity for monitoring the mode purity nor a temperature stabilization.