SBIR-STTR Award

Spontaneous emission is a quantum mechanical process that represents the main source of phase noise in state-of-the-art semiconductor lasers, limiting their coherence, and their suitability for high-speed communication and sensing applications. This proposal aims to develop ultra-high coherence semiconductor lasers on the Silicon/III-V platform with a quantum linewidth of <20 kHz (Phase I) and <5 kHz (Phase II), by tackling this root cause of phase noise in the laser. The laser incorporates two novel concepts to overcome the effects of spontaneous emission: (i) suppression of the quantum noise at its source, by controlling the rate of spontaneous emission; and (ii) mitigation of the effect of the spontaneous emission on the coherence of the laser. Low-cost, wafer-scale, high-throughput techniques will be developed and employed in the fabrication of the laser. The development of this laser on a CMOS compatible silicon platform enables the integration of the laser with other passive and active optical elements and electronics; and its small form factor and low power consumption make it a scalable solution for next-generation high-speed coherent communication and sensing applications.

Keywords:
Hybrid Si/III-V Semiconductor Lasers, Phase Coherence, Spontaneous Emission Control, Silicon Photonics, Coherent Communication, Lidar

This proposal aims to develop Quantum Noise Controlled Lasers or QNCLs for integrated photonic transmitters and receivers for high-speed optical communication systems. The laser is based on the novel quantum noise control paradigm where the engineering of the laser structure controls the amount of spontaneous emission injected into the lasing mode, which is the main source of noise in state-of-the-art semiconductor lasers. The reduction of laser phase noise is critical for optical transmitters and receivers in high-speed (Tbps) coherent communication links employing advanced modulation formats. In addition to the very narrow linewidth (<5 kHz), this effort will develop key features of the laser that are major enablers for integrated photonic circuits: very low sensitivity to optical feedback, which eliminates the need for integrated optical isolators; and high output power, which is necessary to overcome losses in integrated waveguides and modulators. High speed communication using advanced modulation formats will be demonstrated using the QNCL in a coherent optical communication link.