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Method of Coating Optical Device Facets with Dielectric Layers and Device Made Therefrom


Optically Controlled Laser, Gain Quenched Laser Logic

Technical Challenge:

When multiple (integrated) optical devices are fabricated using microelectronics fabrication techniques, it is useful to be able to simultaneously increase the reflectance of all facets of all optical devices. The reflectance of an optical facet can be increased by precise deposition of dielectric layers of known thicknesses and refractive indices. The problem is how to deposit coatings on integrated optical devices that have small optical facets perpendicular to the plane of the substrate upon which they are fabricated. Typically, the optical facets have multiple orientations and are only a few (about 5) microns high within etched wells on the substrate. The challenge is to simultaneously increase the reflectance of all optical device facets by coating all of these small facets in a manner that is compatible with microelectronics fabrications technologies.


This method makes use of conformal coating techniques available with microelectronics fabrication processes to apply dielectric layers to surfaces of optical devices. These conformal deposited dielectric layers can be used to increase the reflectance for optical device facets. Many conformal coating processes for dielectrics can be applied to this method. A Plasma-Enhanced, Chemical Vapor Deposition (PECVD) process has been demonstrated to provide the ability to conformal coat optical device facets with dielectrics that increase the reflectance of those facets in a controlled manner. By using conformal dielectric deposition processes, multiple facets with multiple orientations can be simultaneously coated. This is a method that is compatible with the fabrication of photonic integrated circuits

Demonstration Capability:

There is no demonstration available for this technology.

Potential Commercial Application(s):

This technology is used in the fabrication of integrated semiconductor lasers with cavities that are shorter and where power consumption is lower when the reflectance of those laser mirrors (facets) has been increased above the reflectance available from uncoated facets.

Patent Status:

United States Patent Number 6,835,581

Reference Number: 1190

If you are interested in exploring this technology further, please express your interest in writing to the:

National Security Agency
NSA Technology Transfer Program
9800 Savage Road, Suite 6541
Fort George G. Meade, Maryland 20755-6541


Date Posted: Jan 15, 2009 | Last Modified: Apr 20, 2010 | Last Reviewed: Apr 20, 2010