Improved power and efficiency for tapered lasers with optimized photonic crystal structures

Xiaolong Ma; Hongwei Qu; Shaoyu Zhao; Xuyan Zhou; Yuzhe Lin; Wanhua Zheng

doi:10.1117/12.2284461

24 October 2017 Improved power and efficiency for tapered lasers with optimized photonic crystal structures

Xiaolong Ma, Hongwei Qu, Shaoyu Zhao, Xuyan Zhou, Yuzhe Lin, Wanhua Zheng

Proceedings Volume 10457, AOPC 2017: Laser Components, Systems, and Applications; 104571O (2017) https://doi.org/10.1117/12.2284461
Event: Applied Optics and Photonics China (AOPC2017), 2017, Beijing, China

Abstract

High power and high beam quality laser sources are required in numerous applications such as nonlinear frequency conversion, optical pumping of solid-state and fiber lasers, material processing and others. Tapered lasers can provide a high output power while keeping a high beam quality. However, the conventional tapered lasers suffer from a large vertical beam divergence. We have demonstrated 2-mm long tapered lasers with photonic crystal structures. A high beam quality and a narrow vertical divergence are achieved.

In this paper, we optimized the photonic crystal structure and fabricated a 4-mm long tapered laser to further increase the output power and the wall-plug efficiency. Compared with our precious wafer, the optimized structure has a lower doping level to reduce the internal loss. The period of the photonic crystal structure and the thickness of the upper cladding are also reduced. The device has a 1-mm long ridge-waveguide section and a 3-mm long tapered section. The taper angle is 4°. An output power of 7.3 W is achieved with a peak wall-plug efficiency of 46% in continuous-wave mode. The threshold current is around 500 mA and the slope efficiency is 0.93 W/A. In pulsed mode, the output power is 15.6 W and the maximum wall-plug efficiency is 48.1%. The far-field divergence with full width at half maximum is 6.3° for the lateral direction at 3 A. The vertical far-field beam divergence is around 11° at different injection levels. High beam qualities are demonstrated by beam quality factor M² of 1.52 for the lateral direction and 1.54 for the vertical direction.

Citation Download Citation

Xiaolong Ma, Hongwei Qu, Shaoyu Zhao, Xuyan Zhou, Yuzhe Lin, and Wanhua Zheng "Improved power and efficiency for tapered lasers with optimized photonic crystal structures", Proc. SPIE 10457, AOPC 2017: Laser Components, Systems, and Applications, 104571O (24 October 2017); https://doi.org/10.1117/12.2284461

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available