Abstract: The present invention provides, in at least one embodiment, a system and method for power control of lasers. The system includes a device's control signal fed into a laser. The laser can be a master oscillator power amplifier (MOPA) fiber laser. The device includes an equivalent model circuit representing at least one parameter of the laser, such as the gain fiber inversion in the power amplifier. The device measures the power at the equivalent model circuit. Then, the device uses its feedback signal to control and/or adjust the output power control signal fed into the laser based on the measured power. By controlling the power fed into the laser, the laser can be operated at much lower frequencies while keeping the laser power within acceptable limits.

Abstract: A circuit apparatus for driving short current pulses through a laser diode is disclosed. The circuit allow fast recovery time, comparable to the pulse duration. This enables high duty cycle pulse trains and bursts. The fast recovery is achieved by a passively self gated charging of the pulse circuit.

Abstract: A method for control of excess pump power in an optical amplifiers is disclosed. In one particular exemplary embodiment the method comprises a state model for the amplifier gain medium ground energy level inversion and a closed loop control tracking a desired degree of excess pump power.

Abstract: The present invention provides, in at least one embodiment, a scheme which is effective in suppressing detrimental coherence effects such as random backscatter. In a fiber laser having a master oscillator power amplifier design, inserting a decorrelator in between the master oscillator and a first power amplifier or inserting a decorrelator in between the first power amplifier and a second power amplifier to reduce random backscatter, which allows for much more energy to be stored and higher gain without the risk of catastrophic optical damage, thus increasing the peak power that can be delivered as useful laser power. Backscattering can be further reduced by having the master oscillator depolarized, injection locked, and spectrally broadened to reduce the coherence length of the master oscillator.

Abstract: The present invention provides an amplified spontaneous emission fiber optic source having high optical power (>20 mW) and a spectral broadband emission (>70 nm) centered near a wavelength of 1060 nm. In an embodiment of the invention, the fiber source comprises a combination of Yb-doped and Nd-doped silica fibers in a dual-pumping configuration. The Yb-doped optical fiber has a peak absorption coefficient of 350 dB/nm at 977 nm band, and the Nd-doped fiber used has a dopant concentration of 500 ppm-wt in a glass host of aluminum-germano-phospho-silicate. A combination of these two doped-fibers along with optical spectral filtering provides a broadband spectrum giving coherence length <7 ?m (in air), which is well suited for optical coherence imaging.

Abstract: The present invention provides an amplified spontaneous emission fiber optic source having high optical power (>20 mW) and a spectral broadband emission (>70 nm) centered near a wavelength of 1060 nm. In an embodiment of the invention, the fiber source comprises a combination of Yb-doped and Nd-doped silica fibers in a dual-pumping configuration. The Yb-doped optical fiber has a peak absorption coefficient of 350 dB/nm at 977 nm band, and the Nd-doped fiber used has a dopant concentration of 500 ppm-wt in a glass host of aluminum-germano-phospho-silicate. A combination of these two doped-fibers along with optical spectral filtering provides a broadband spectrum giving coherence length <7 ?m (in air), which is well suited for optical coherence imaging.