Abstract

A novel process is proposed for the volume diffractive element (Bragg grating) fabrication in photosensitive silicate glasses doped with silver, cerium, fluorine, and bromine. The process employs a photo-thermo-refractive (PTR) glass of high purity exposed to ultraviolet (UV) radiation of a He--Cd laser at 325 nm followed by thermal development at temperatures from 480.degree. C. to 580.degree. C., preferably at 520.degree. C., from several minutes to several hours. Absolute diffraction efficiency up to 95% was observed for 1 mm thick gratings. Maximum spatial frequency recorded in PTR glass was about of 10,000 mm.sup.-1. No decreasing of diffraction efficiency were detected at low spatial frequencies. Original glasses were transparent (absorption coefficient less than 1 cm.sup.-1) from 350 to 4100 nm. Induced losses in exposed and developed glass decreased from 0.3 to 0.03 cm.sup.-1 between 400 and 700 nm, respectively, and did not exceed 0.01-0.02 cm.sup.-1 in the infrared (IR) regio

Document Type

Patent

Patent Number

US 6,586,141

Application Serial Number

09/648,293

Issue Date

7-1-2003

Current Assignee

UCFRF

Assignee at Issuance

UCFRF

College

College of Optics and Photonics

Department

CREOL

Allowance Date

1-27-2003

Filing Date

8-24-2000

Assignee at Filing

UCFRF

Filing Type

Nonprovisional Application Record

Donated

no

Download Patent

Share

COinS