Ondax, Inc.

Gregory J Steckman

Christophe Moser

Frank Havermeyer

Lawrence Ho

The disclosed invention is an external cavity laser with a volume holographic VHG output coupler. The facet of the VHG is coated with a very high reflectivity coating (HR close to 100%) for the purpose of reflecting the second harmonic (SH) light generated intra-cavity. The HR coating for the SH light has also an anti-reflection (AR) coating at the fundamental wavelength. The reflected second harmonic (SH) light is either reflected directly out of the cavity by the VHG or back to the cavity towards the optics that deflect the SH light out of the cavity.

Output coupler for external cavity laser

The invention describes a system for the measurement of volume holograms on a wafer scale that permits high-resolution and high throughput measurement of grating parameters. The invention uses a collimated beam of a fixed wavelength light source that is transmitted through the wafer to be tested. The transmitted beam is imaged with a lens onto a sensor. The sensor is used to measure the beam power under a variety of conditions, including without a wafer in place, so that the various measurements can be used to determine grating characteristics. The measurement data produced includes values for grating spacing, tilt angle, and diffraction efficiency with a high spatial resolution.

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Glendora, CA, United States of America

Gregory J Steckman