Cavity Physics and Tunneling Modulation of Microcavity Laser Toward 10 fJ/bit for Future Optical Networks
Abstract
The invention of semiconductor lasers (1962) by Hall and Holonyak have revolutionized the world of display, solid-state lighting, and optical fiber communication. The development of quantum-wells in edge-emitting laser further improved carrier confinement and reduced laser threshold to ~ 10 mA in today commercial DFB laser used in Silicon Photonics. However, the high threshold limits the efficiency in today optical data link to > 30 pJ/bit. Since 1979, the development of surface emitting laser (SEL) with semiconductor DBRs and oxide-confined aperture provide a clear path for low power operation of semiconductor laser. Today, oxide-VCSEL has already made the revolution of data communications with link power ~ 15 pJ/bit. However, the ever-increasing demands for high bandwidth used in internet, IoT and 5G wireless, the data link requires ultralow energy/bit by 100x (~ 0.2 pJ/bit). This implies semiconductor lasers need to increase the speed by 10x and reduce the power by 10x toward 20 fJ/bit. In this proposal, we offer to study fundamental cavity scaling quantum physics to achieve energy-efficient data transmission toward ~ 20 fJ/bit. The microscopic processes of stimulated photon generation rate, thermally limited e-h recombination lifetimes, carrier temperature, stimulated photon-assisted tunneling and direct tunneling modulation in microcavity laser are of great interest to investigate and understand. Scaling laser cavity volume to achieve ITH~0.1 mA approach can improve energy/bit by 10x toward 100 fJ/bit. Three-terminal transistor laser has demonstrated the advantage of ÒshortÓ recombination lifetime (~23 ps) over current diode laser (~ 200 ps) and an ultrafast direct tunneling laser modulation (< 50 fs) at collector junction. Thus, a tunneling modulated can realize laser BW > 200 GHz for data rate > 400 Gb/s. In Phase 1 (budget $149,571), our goal is to study stimulated physics of microcavity scaling for low threshold laser and develop method to accurately determine cavity temperature due to self-heating. In Phase 2 (budget $149,392), our goal is to study cavity physics of thermally-limited e-h recombination lifetimes, stimulated photon-generation rate, and the development a microwave-thermal laser model for optimizing device geometry to improve lifetimes to < 30 ps for bandwidth > 50 GHz. In Phase 3 ($149,279), we will establish a microwave-thermal-tunneling laser model for fast cavity e-h recombination lifetime and tunneling modulation to improve laser BW toward > 200 GHz for advancing high capacity per fiber of > 400 Gb/s PAM-4.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2022
- Source ID
- W911NF2210046
Entities
People
- Milton Feng
Organizations
- Army Contracting Command
- United States Army
- University of Illinois Urbana–Champaign