Tunable system for generating an optical pulse based on a double-pass semiconductor optical amplifier

A system for generating a shaped optical pulse comprising:

• an optical circulator for receiving a first optical pulse;
• a semiconductor optical amplifier optically connected to the optical circulator to receive the first optical pulse and configured so as to amplify at least a portion of the received first optical pulse and output a first amplified pulse;
• a fiber Bragg grating optically connected to the semiconductor optical amplifier for selectively reflecting the first amplified pulse to the semiconductor optical amplifier, and
• wherein the semiconductor optical amplifier receives the reflected first amplified pulse from the fiber Bragg grating and amplifies at least a portion of the reflected first amplified pulse so as to create a second amplified optical pulse, the second amplified output being received by the optical circulator and outputted from the optical circulator as the shaped optical pulse.