Ultralow Threshold Microlasers.
Abstract
This final technical report summarizes advances to push the limits of ultralow threshold microlaser VCSEL design implementation, and performance. The main results are summarized: (1) Values of spontaneous emission coupling factor B(beta) in the range between 10(exp -2) and 10(exp -1) lead to comparatively low turn-on delay for both on-on and on-off modulation. Spontaneous emission factors lying between 10(exp -2) and 10(exp -1) are more attractive than devices with B approx. 1. (2) With reduction of aperture size to less than 5x5 sq micrometers. the internal quantum efficiency decreases owing to carrier losses resulting from current spreading and carrier out-diffusion, the round-trip loss increases due to excess diffraction and scattering losses. (3) Modal noise and speckle visibility in Gb/s multimode waveguide interconnect systems depends on a complex interplay of carrier dynamics, spontaneous emission factor, gain compression, and device dimensions. Scaled low-power microlasers exhibit modal noise comparable to large incoherent multimode devices. (4) The series resistance of microlasers has been explored by fabricating low resistance, low-threshold current, and intracavity-contacted devices.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1997
- Accession Number
- ADA336389
Entities
People
- A. F. Levi
- Paul Daniel Dapkus
Organizations
- University of Southern California