Light conducting fibers of quartz glass

• US 3,966,300 A
• Filed: 01/22/1973
• Issued: 06/29/1976
• Est. Priority Date: 01/24/1972
• Status: Expired due to Term

• Current Assignee: Jenaer Glaswerk Schott & GEN
• Original Assignee: Jenaer Glaswerk Schott & GEN
• Inventors: Bernsee, Gerhard
• Primary Examiner(s): Rubin, David H.
• Application Number:
  US05/325,377
• Time in Patent Office: 1,254 Days
• Field of Search: 350/96
• US Class Current: 385/142
• CPC Class Codes: C03B 2201/02 Pure silica glass, e.g. pure fused quartz
• CPC Class Codes: C03B 2201/04 Hydroxyl ion (OH)
• CPC Class Codes: C03B 2201/23 doped with hydroxyl groups
• CPC Class Codes: C03B 37/01211 by inserting one or more rods or tubes into a tube
• CPC Class Codes: C03C 13/045 Silica-containing oxide glass compositions
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/06 the relative position of the fibres being the same at both ends, e.g. for transporting images
• CPC Class Codes: G02B 6/102 for infrared and ultraviolet radiation

Abstract

Light-conducting optical fibers in which both the core and sheath consist essentially of quartz glass are provided by encasing a relatively anhydrous quartz glass core with a quartz glass sheath having a sufficiently high water content to lower the refractive index thereof. The fibers are ideally suited for the transmission of ultraviolet light with maximum efficiency.

Claims

1. A light-conducting optical fiber comprising a quartz glass core consisting of SiO₂, 0-20 ppm H₂ O, and up to 1 ppm trace elements, and having a refractive index N₁, encased by a quartz glass sheath consisting of SiO₂, 800-4000 ppm H₂ O, and up to 1 ppm trace elements, and having a refractive index N₂, N₁ being greater than N₂.

2. An optical fiber according to claim 1 wherein the difference in refractive index between the quartz glass core and the quartz glass sheath is at least 0.0001.

3. An optical fiber according to claim 1 wherein the quartz glass core is anhydrous quartz glass having a water content of less than about 5 ppm.

4. An optical fiber according to claim 1 wherein the difference in water content between the quartz glass core and the quartz glass sheath is about 1,000 ppm.

5. An optical fiber according to claim 1 wherein the refractive index of the quartz glass core is about N_H 1.45647.

6. An optical fiber according to claim 5 wherein the refractive index of the quartz glass sheath is about N_H 1.45637.

7. An optical fiber according to claim 5 having an acceptance angle θ

of about 1.96°

wherein sine θ

= √

N₁² - N₂².

8. In a fiber optic bundle, the improvement which comprises using an optical fiber according to claim 1.

9. A coherent fiber optic bundle according to claim 8.

10. An optical fiber according to claim 1 wherein the water content of the sheath glass is not more than 2500 ppm.

11. An optical fiber according to claim 10 wherein the water content of the core glass is about 0.5 to 5 ppm.

12. An optical fiber according to claim 1 wherein the refractive index of the core glass is 1.45857 to 1.45856 and that of the sheath glass is 1.458555 to 1.45817.

13. An optical fiber according to claim 1 wherein the refractive index of the core glass is 1.45857 to 1.458565.

14. An optical fiber according to claim 1 wherein the refractive index of the sheath glass is 1.45849 to 1.45823.

15. An optical fiber according to claim 1, having an acceptance angel θ

of at least about 0.6°

wherein sine θ

= √

N₁² - N₂².