Integrated, Low-Jitter Monolithic Quantum Dot Mode-Locked Lasers

High precision digitization of very high frequency waveforms requires sample clocks that have extremely low timing jitter and low noise; any error in timing appears as an error in the sampled signal itself, greatly reducing the dynamic range of the sampled signal. Furthermore, real world and military requirements dictate compact, robust, and inexpensive solutions. Mesa Photonics, LLC and the University of New Mexico propose to develop a low jitter, low noise, completely monolithic next generation optical clock that is based on passively mode-locked quantum dot diode lasers, which will be useful for optical sampling, photonic ADCs and optical receivers. By removing the complexity of active mode-locking, these devices will be more robust and compact than actively mode-locked systems. In addition, these passively mode-locked lasers operate in a wavelength region that is ideal for silicon photonics, about 1240 nm. This wavelength region is below the bandgap of silicon, making the wavelength region suitable for silicon waveguides and SiGe and Si detectors. This SBIR effort is designed to better understand jitter and noise sources in quantum dot-based passively mode-locked diode lasers and to develop a monolithic optical oscillator that is suitable for high dynamic range, broadband digital receiver systems and optical analog-to-digital converter (ADC) technology.