Erbium-doped GaN bulk crystals as a gain medium for eye-safe high energy lasers

Z. Y. Sun; Q. W. Wang; J. Li; J. Y. Lin; H. X. Jiang

doi:10.1117/12.2293166

22 February 2018 Erbium-doped GaN bulk crystals as a gain medium for eye-safe high energy lasers

Z. Y. Sun, Q. W. Wang, J. Li, J. Y. Lin, H. X. Jiang

Proceedings Volume 10528, Optical Components and Materials XV; 105280E (2018) https://doi.org/10.1117/12.2293166
Event: SPIE OPTO, 2018, San Francisco, California, United States

Abstract

High energy lasers (HELs) operating around 1.5 μm are considered eye-safe and are highly sought-after for use in defense, industrial processing, communications, medicine, spectroscopy, imaging and various other applications where the laser is expected to travel long distances in free space. Compared to YAG, GaN has a higher thermal conductivity, lower thermal expansion coefficient, and lower temperature coefficient of the refractive index (dn/dT) around 1.5 μm. Hence, HELs based on erbium doped GaN (Er:GaN) are expected to outperform those based on Er:YAG in terms of average power, power density, temperature stability and beam quality. Here, we provide a brief overview on the progress made in authors’ laboratory for the realization of freestanding Er:GaN wafers of 2-inches in diameter with a thickness on the millimeter scale. These freestanding wafers were obtained via growth by hydride vapor phase epitaxy (HVPE) in conjunction with a laser-lift-off process. Optical absorption and resonantly excited photoluminescence emission spectra have enabled the construction of energy level diagrams pertaining to the excitation and emission mechanisms of Er:GaN eye-safe HELs operating around 1.5 μm. The results have shown that the common excitation and emission scheme of Er:YAG is not entirely applicable to achieve Er:GaN eye-safe lasers. In addition to higher thermal conductivity of Er:GaN over Er:YAG gain medium, Er:GaN eye-safe lasers appear to possess lower quantum defects than Er:YAG lasers.

Conference Presentation

Citation Download Citation

Z. Y. Sun, Q. W. Wang, J. Li, J. Y. Lin, and H. X. Jiang "Erbium-doped GaN bulk crystals as a gain medium for eye-safe high energy lasers ", Proc. SPIE 10528, Optical Components and Materials XV, 105280E (22 February 2018); https://doi.org/10.1117/12.2293166

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