Advanced portable DIAL hygrometer using high-power pulsed laser diodes with fiber-optical cascade collimator

Generating photoacoustic signals using high-peak power pulsed laser diodes

Photoacoustic signals are usually generated using bulky and expensive Q-switched Nd:YAG lasers, with limited scope for varying the pulse repetition frequency, wavelength and pulse width. An alternative would be to use laser diodes as excitation sources; these devices are compact, relatively inexpensive, and available in a wide variety of NIR wavelengths. Their pulse duration and repetition rate...

High-Power Pulsed 2-μm Tm-Doped Fiber Laser

Tm3+-doped fiber is very suitable for producing ~2-μm laser emission due to its several unique advantages. First, Tm3+-doped fiber has a strong absorption spectrum that has good overlap with the emission spectrum of commercially available AlGaAs laser diodes. Second, the specific energy-level structure of Tm3+ ions provides the Tm3+-doped fiber laser (TDFL) quantum efficiency close to two throu...

Catastrophic optical damage of high power InGaAs/AlGaAs laser diodes

The defects generated by the catastrophic optical degradation (COD) of high power laser diodes have been examined using cathodoluminescence (CL). Discontinuous dark lines that correspond to different levels of damage have been observed along the ridge. Finite element methods have been applied to solve a physical model for the degradation of the diodes that explicitly considers the thermal and m...

Advanced Optical Fibers for High Power Fiber Lasers

Photonic power delivery through optical fiber using very high power laser diode arrays

Described is a system that will provide isolated electric power for a circuit that drives the core reset of a pulsed power modulator. This can be accomplished by coupling light from a number of diode laser bars to bundles of 200 urn multimode optical fibers. This is then coupled to photo-voltaic power converters that will deliver 16 V 29 mA of electricity from 1 watt of optical power. Spot size...