Optical amplifier arrangement

摘要

An optical amplifier which integrates a pre-amplifier and a power amplifier in a single rectangular active medium to enable amplification of low power ultra-short pulses to optimal power levels. A seed beam passes through the amplification medium along a first pre-amplification path making multiple traverses of the medium. It is imaged back along the first path to make a double pass of the medium as a pre-amplifier. The beam is then re-imaged into the medium again on a second power amplification path, making multiple traverses of the medium in a single pass. The paths are independent but overlap so that efficient power extraction is achieved. Embodiments based on all passive components are described.

主权项

1. Optical amplifier apparatus comprising:
an amplification medium that has a rectangular cross-section with a long edge and a short edge, at least two highly reflective mirrors, wherein the amplification medium is arranged between the at least two highly reflective mirrors, wherein the short edge of the cross-section is along the x-axis, the long edge is along the y-axis, and the z-axis is the optical axis, and wherein the x-, y- and z-axes constitute a rectangular system of coordinates, wherein a beam, emitted from an oscillator, makes at least one reflection from each of the at least two highly reflective mirrors to define a path comprising a plurality of traverses through the amplification medium in the xz plane, the beam making a double pass of a first path in a pre-amplifier stage and a single pass of a second path in a power amplifier stage, and wherein the first and second paths are independent and overlap in the amplification medium.