Merged beam laser design for reduction of gain-saturation and two-photon absorption in high power single mode semiconductor lasers

• Published in: Optics express Vol. 21; no. 7; pp. 8276 - 8285
• Main Authors: Lysevych, M, Tan, H H, Karouta, F, Fu, L, Jagadish, C
• Format: Journal Article
• Language: English
• Published: United States 08.04.2013
• Subjects: Absorption; Amplifiers, Electronic; Equipment Design; Equipment Failure Analysis; Lasers, Semiconductor; Photons
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.21.008276

In this paper we report a method to overcome the limitations of gain-saturation and two-photon absorption faced by developers of high power single mode InP-based lasers and semiconductor optical amplifiers (SOA) including those based on wide-waveguide or slab-coupled optical waveguide laser (SCOWL) technology. The method is based on Y-coupling design of the laser cavity. The reduction in gain-saturation and two-photon absorption in the merged beam laser structures (MBL) are obtained by reducing the intensity of electromagnetic field in the laser cavity. Standard ridge-waveguide lasers and MBLs were fabricated, tested and compared. Despite a slightly higher threshold current, the reduced gain-saturation in MBLs results in higher output power. The MBLs also produced a single spatial mode, as well as a strongly dominating single spectral mode which is the inherent feature of MBL-type cavity.