20 GHz Analog Fiber-Optic Link Using Injection-Locked Laser Diodes

Enhancement of the modulation bandwidth of a laser diode to beyond 20 GHz can be achieved using external optical injection from a master laser oscillator. Injection of an optical signal into a semiconductor laser modifies the resonant coupling between the carriers and circulating optical field. Enhanced bandwidths into the millimeter-wave frequency modulation regime are calculated to be achievable with current laser diodes. Exploiting the novel physics underlying the dynamics in an injection-locked laser diode, commercially-available devices with good noise and stability characteristics can be used for wide bandwidth applications. The injection-locked laser diode can be used as the core element of optical transceivers with improved modulation and noise characteristics.| Benefits: A low-noise, bandwidth-enhanced optical modulator is a critical enabling technology for a variety of applications requiring transmission of data or information in analog format. The research will demonstrate a new concept for an advanced modulator using laser diodes. The concept also can be utilized in the optical control of microwaves and signal-processing applications.|