Low noise surface emitting laser for multimode optical link applications
AssigneeHewlett-Packard Company
InventorsShih-Yuan Wang, Michael R. Tan, Andreas Weber, Kenneth H. Hahn
Life of this patent
Estimating the term…
Abstract
The present invention provides a low noise multimode VCSEL that can be used to transmit data reliably on multimode optical media at data rates up to and exceeding 1 gigabit per second with bit error rates less than 1.times.10.sup.-9 errors/bit. In contrast to conventional multimode lasers where optimal mirror reflectivity is designed for maximum power output, in the present invention mirror reflectivity is increased to a point where the output power is less than half the maximum output power. Preferably, the reflectivity of the first and second mirror regions of the multimode laser is high, typically greater than 99.5%.
Claims13
A low noise multimode vertical cavity surface emitting laser comprised of:
- a first mirror region, wherein the reflectivity of the first mirror is greater than 99.5%;
- an active region positioned between the first mirror region and a second mirror region, wherein the reflectivity of the second mirror is greater than 99.5%, wherein the reflectivity of the first mirror region and the second mirror region are designed to result in an output power of the multimode vertical cavity surface emitting laser that is less than half the optimal power output;
- and
- a first optical lossy region and a second optical lossy region, wherein the distance between the first and second optical lossy regions is greater than the lateral dimensions of the optical cavity of the multimode laser, and further wherein the first and second optical lossy regions are positioned so that they do not significantly interfere with the outermost modes of the multimode vertical cavity surface emitting laser.
A low noise multimode vertical cavity surface emitting laser comprised of:
- a first mirror region, wherein the reflectivity of the first mirror region is greater than 99.5%;
- an active region positioned between the first mirror region and a second mirror region, the second mirror region being comprised of a second Bragg mirror region and an electrode having reflective properties formed on the surface of the second mirror region, wherein the reflectivity of the first mirror region is greater than 99.5% and the reflectivity of the second mirror region is greater than 99.5% and further wherein the reflectivity of the first mirror region and the second mirror region are designed to result in an output power of the multimode vertical cavity surface emitting laser that is less than half the maximum power output;
- and
- optical lossy regions formed in the second mirror region, wherein the distance between the optically lossy regions is greater than the lateral dimensions of the optical cavity of the multimode laser.
A method of making a multimode laser including the steps of:
- forming a first mirror region on a substrate, the first mirror region having a reflectivity greater than 99.5%;
- forming an active region on a first surface of the first mirror region;
- forming a second mirror region on the surface of the active region, such that the active region is positioned between the first mirror region and the second mirror region, the second mirror region having a reflectivity greater than 99.5%, wherein the output power of the multimode vertical cavity laser is less than half the optimum output power;
- and
- forming a first and second optically lossy region, wherein the distance between the first and second optically lossy regions is greater than the lateral dimensions of the optical cavity, wherein the optical lossy regions are positioned so that the optically lossy regions do not significantly interfere with the outermost modes of the multimode vertical cavity surface emitting laser.
Dependencies are inferred from the claim text.