Diode laser having reduced beam divergence

US11677214B2 · kind B2 · utility

Assignee

• FERDINAND-BRAUN-INSTITUT GGMBH, LEIBNIZ-INSTITUT FÜR HÖCHSTFREQUENZTECHNIK · DE

Inventors

• Anissa Zeghuzi · Berlin, DE
• Jan-Philipp Koester · Berlin, DE
• Hans Wenzel · Santa Ana, US
• Heike Christopher · Berlin, DE
• Andrea Knigge · Königs Wusterhausen, DE

Key dates

• Filing date: Mar 31, 2021
• Grant date: Jun 13, 2023
• Expiry date: Apr 15, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S2301/18
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present disclosure relates to a diode laser having reduced beam divergence. Some implementations reduce a beam divergence in the far field by means of a deliberate modulation of the real refractive index of the diode laser. An area of the diode laser (e.g., the injection zone), may be structured with different materials having different refractive indices. In some implementations, the modulation of the refractive index makes it possible to excite a supermode, the field of which has the same phase (in-phase mode) under the contacts. Light, which propagates under the areas of a lower refractive index, obtains a phase shift of π after passing through the index-guiding trenches. Consequently, the in-phase mode is supported and the formation of the out-of-phase mode is prevented. Consequently, the laser field can, in this way, be stabilized even at high powers such that only a central beam lobe remains in the far field.