Waveguide having a phase-matching region

US10578876B1 · kind B1 · utility

Assignee

• Facebook Technologies, LLC · US

Inventors

• Wai Sze Tiffany Lam · Bothell, US
• Ningfeng Huang · Redmond, US
• Alexander Koshelev · Redmond, US
• Hee Yoon Lee · Bellevue, US
• Austin Lane · Redmond, US
• Giuseppe Calafiore · Redmond, US

Key dates

• Filing date: Sep 10, 2018
• Grant date: Mar 3, 2020
• Expiry date: Sep 10, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B2027/0178
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A waveguide is provided including first and second diffraction gratings and a phase-matching region conterminous with the first and second diffraction gratings and disposed in an optical path between the gratings. For an optical beam propagating along the optical path, the first grating adds a first phase shift to the optical beam reflecting from the first grating, the second grating adds a second phase shift to the optical beam reflecting from the second grating, and the phase-matching region adds a matching phase shift to the optical beam reflecting from the phase-matching region. The matching phase shift is between minimum and maximum values of the first and second phase shifts.