This paper, originally published on 27 April 2016, was replaced with a corrected/revised version on 8 June 2016. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

The purpose of wavelength-beam combining (WBC) is to improve the output power of a multi-wavelength laser system while maintaining the quality of the combined beam. This technique has been primarily proposed for industrial applications, such as metal cutting and soldering, which require optical peak power between kilowatts and megawatts. In order to replace the bulkier solid-state lasers, we propose to use the WBC technique for photoacoustic (PA) applications, where a multi-wavelength focused beam with optical peak power between hundreds of watts up to several kilowatts is necessary to penetrate deeply into biological tissues. In this work we present an analytical study about the coupling of light beams emitted by diode laser bars at 808 nm, 880 nm, 910 nm, 940 nm, and 980 nm into a < 600-μm core-diameter optical fiber for PA endoscopy. In order to achieve an efficient coupling it is necessary to collimate the beams in both fast and slow axes by means of cylindrical lenses and to use partial reflection mirrors at 45° tilt. We show an example of beam collimation using cylindrical lenses in both fast and slow axes. In a real PA scenario, the resulting beam should have a sufficient peak power to generate significant PA signals from a turbid tissue>.

Date Published: 27 April 2016
PDF: 12 pages
Proc. SPIE 9888, Micro-Optics 2016, 988807 (27 April 2016); doi: 10.1117/12.2225954

Published in SPIE Proceedings Vol. 9888:
Micro-Optics 2016
Hugo Thienpont; Jürgen Mohr; Hans Zappe; Hirochika Nakajima, Editor(s)