Coating for optical devices

• US 4,749,255 A
• Filed: 12/09/1985
• Issued: 06/07/1988
• Est. Priority Date: 12/09/1985
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Inventors: Chakrabarti, Utpal K., Chin, Aland K., Przybylek, George J., Zydzik, George J., Van Uitert, LeGrand G.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/806,492
• Time in Patent Office: 911 Days
• Field of Search: 350/164, 350/1.1, 350/319, 350/320, 372/96, 372/49, 372/48
• US Class Current: 372/45.012
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/30 by electron bombardment
• CPC Class Codes: G02B 1/113 using inorganic layer materials only
• CPC Class Codes: H01S 5/028 Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers

Abstract

Disclosed is a device including a surface coating for passivation or anti-reflection, and a method of manufacture. The coating comprises ZrO₂ doped with yttrium, magnesium or calcium. The doped ZrO₂ is preferably deposited on the device surface by electron-beam evaporation from a single crystal source of ZrO₂ and Y₂ O₃, MgO or CaO.

Claims

1. An optical device including a semiconductor material selected from the group consisting of III-V and II-VI semiconductors, said device comprising a coating formed by depositing from a source material over at least a portion of the surface of the device, characterized in that the coating comprises ZrO₂ and an oxide of an element selected from the group consisting of yttrium, magnesium, and calcium, and that said source material is a single crystal of ZrO₂ doped with one of said oxides.

2. The device according to claim 1 wherein the device is a laser with mirror facets and the coating covers at least one facet.

3. The device according to claim 2 wherein the device is a channeled substrate buried heterostructure capable of withstanding current pulses of 1 amp.

4. The device according to claim 2 wherein the device is a distributed feedback laser which emits light having a single longitudinal mode.

5. The device according to claim 1 wherein the thickness of the coating is an odd multiple of λ

/2n where λ

is the wavelength of the light emitted or received by the device and n is the index of refraction of the coating.

6. The device according to claim 1 wherein the thickness of the coating is an odd multiple of λ

/4n where λ

is the wavelength of the light emitted or received by the device and n is the index of refraction of the coating.

7. The device according to claim 1 wherein the coating consists essentially of ZrO₂ and Y₂ O₃.

8. The device according to claim 7 wherein the proportion of ZrO₂ is within the range 88-92 mole percent and the proportion of Y₂ O₃ is within the range 8-12 mole percent.

9. A method of fabricating an optical device including a semiconductor material selected from the group consisting of III-V and II-VI semiconductors, including coating at least a portion of the device surface comprising the steps of:

providing a single crystal material comprising ZrO₂ and an oxide of an element selected from the group consisting of yttrium, magnesium, and calcium in a vacuum environment; and

electron-beam evaporating the material so as to deposit a coating on the semiconductor surface.

10. The method according to claim 9 wherein no oxygen is introduced into the vacuum environment during the evaporation.

11. The method according to claim 9 wherein the material consists essentially of ZrO₂ and Y₂ O₃.

12. The method according to claim 11 wherein the proportion of ZrO₂ is within the range of 88-92 mole percent and the proportion of Y₂ O₃ is within the range 8-12 mole percent.

13. The method according to claim 9 wherein the thickness of the coating is an odd multiple of λ

/2n where λ

is the wavelength of the light emitted or received by the device and n is the index of refraction of the coating.

14. The method according to claim 9 wherein the thickness of the coating is an odd multiple of λ

/4n where λ

is the wavelength of the light emitted or received by the device and n is the index of refraction of the coating.