Photonic integrated circuits based on quantum cascade structures

US9450053B2 · kind B2 · utility

Assignees

• Massachusetts Institute of Technology · US
• Pendar Technologies, LLC · US

Inventors

• Anish K. Goyal · Milpitas, US
• Laurent Diehl · Cambridge, US
• Christian Pfluegl · Arlington, US
• Christine A. Wang · Bedford, US
• Mark F. Witinski · Cambridge, US

Key dates

• Filing date: Jul 25, 2013
• Grant date: Sep 20, 2016
• Expiry date: Jul 25, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S5/2275
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Photonic integrated circuits (PICs) are based on quantum cascade (QC) structures. In embodiment methods and corresponding devices, a QC layer in a wave confinement region of an integrated multi-layer semiconductor structure capable of producing optical gain is depleted of free charge carriers to create a low-loss optical wave confinement region in a portion of the structure. Ion implantation may be used to create energetically deep trap levels to trap free charge carriers. Other embodiments include modifying a region of a passive, depleted QC structure to produce an active region capable of optical gain. Gain or loss may also be modified by partially depleting or enhancing free charge carrier density. QC lasers and amplifiers may be integrated monolithically with each other or with passive waveguides and other passive devices in a self-aligned manner. Embodiments overcome challenges of high cost, complex fabrication, and coupling loss involved with material re-growth methods.