• Integrated MOPA/modulator device produces watt-level output

    Monolithic master oscillator/power amplifier (MOPA) structures capable of high-power, difffraction-limited output offer smaller, lower-cost replacements for many gas and solid-state lasers. Adding high-speed modulation capability makes MOPAs attractive for applications in satellite space communications and telecommunications, and researchers at SDL (San Jose, CA) recently demonstrated that approach by inserting an electro-absorption modulator between the master oscillator and power amplifier. T
    Sept. 1, 1995

    Integrated MOPA/modulator device produces watt-level output

    Monolithic master oscillator/power amplifier (MOPA) structures capable of high-power, difffraction-limited output offer smaller, lower-cost replacements for many gas and solid-state lasers. Adding high-speed modulation capability makes MOPAs attractive for applications in satellite space communications and telecommunications, and researchers at SDL (San Jose, CA) recently demonstrated that approach by inserting an electro-absorption modulator between the master oscillator and power amplifier. The device emitted more than 1 W at 980 nm, and the modulator bandwidth was 5 GHz. Strained quantum wells of InGaAs formed the distributed Bragg reflector (DBR) master oscillator and amplifier region. The front and back mirrors of the DBR cavity were defined by second-order gratings. Light from the oscillator is injected through the front grating into the 500-µm long modulator, then passes to the 1.5-mm gain-guided power amplifier. In a self-homodyne setup, a linewidth of 750 kH¥was determined, and the researchers measured a small-signal modulation bandwidth of about 5 GHz, which they believe is the highest value reported for a monolithically integrated MOPA. This device could find use in free-space optical links for intersatellite optical communications.

    Sign up for Laser Focus World Newsletters
    Get the latest news and updates.

    Voice Your Opinion!

    To join the conversation, and become an exclusive member of Laser Focus World, create an account today!