A tapered semiconductor optical amplifier, capable of delivering up to 0.5 W of power at 795 nm.

For high power applications, single-pass tapered amplifiers are used to amplify light from a ECDL or DBR laser. These single chip devices can provide gain by over a factor of 100 resulting in up to 0.5 W of output power and can be purchased at a number of commonly used wavelengths for atomic physics. Roughly 10 mW of input power is required to saturate the amplifier. In the figure, the injecting light comes in from the right, through a window in the box and is focused down onto the amplifier chip. The amplified light is coupled out of the MOPA with a pair of cylindrical micro-lenses which compensate for the high degree of astigmatism generated in the amplifier. The amplifer chip is water-cooled to help dissipate the heat generated by up to 2 A of current which flows through the MOPA.

A tapered amplifier (inside box, at right) pumped by a two-section DBR laser (top, center of box).