Finisar Corporation

Scott Lehmann

Ashish K Verma

Tsurugi Sudo

Roman Dimitrov

A method for depositing protective coatings on front and rear facets of an optical device, such as a laser die, is disclosed. The protective coatings help prevent laser facet damage common to laser dies manufactured using known processes. In one embodiment, the method for coating the laser die includes placing the laser in an evacuated coating chamber before applying a first coating portion to a first facet of the laser. The first coating portion is applied to the first facet so as to form a protective covering thereon, but is applied at a coating energy that minimizes damage to the as-yet uncoated second facet. The laser is then rotated within the coating chamber, and a full coating is applied to a second facet of the laser. The laser is again rotated, and a full coating is applied atop the first coating portion to the first facet of the laser.

Method for applying protective laser facet coatings

A method for etching facets of a laser die prior to coating in such a way as to control the formation of oxides and metallic films on the facet is disclosed. In one embodiment, the method includes placing a wafer on which the laser is included in the interior volume of an etching chamber. Nitrogen is introduced into the interior volume to define a nitrogen-rich environment. The laser facet is then etched in the nitrogen-rich environment with argon delivered from an ion gun. In another embodiment, the method includes placing the laser in an ion beam etching chamber, then physically etching the facet of the laser with an ion beam that includes an argon/nitrogen mixture. The laser facet(s) can then be coated as desired. The etching method reduces the incidence of leakage current during operation of the laser die caused by metallic film formation on the facet before coating.

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Oakland, CA, United States of America

Scott Lehmann