Picosecond pulse generation in monolithic GaN-based multi-section laser diodes

Katarzyna Holc; Thomas Weig; Wilfried Pletschen; Klaus Köhler; Joachim Wagner; Ulrich T. Schwarz

doi:10.1117/12.2001774

4 March 2013 Picosecond pulse generation in monolithic GaN-based multi-section laser diodes

Katarzyna Holc, Thomas Weig, Wilfried Pletschen, Klaus Köhler, Joachim Wagner, Ulrich T. Schwarz

Proceedings Volume 8625, Gallium Nitride Materials and Devices VIII; 862515 (2013) https://doi.org/10.1117/12.2001774
Event: SPIE OPTO, 2013, San Francisco, California, United States

Abstract

We develop a monolithic picosecond laser pulse generator, based on the classical design of a group-III-nitride Fabry-Pérot laser diode with electrically separated ridge sections. We use two different multi-section design variants, with the absorber section placed either in the center or at the end of the ridge. Profiting from the very low lateral conductivity in the p-type GaN top contact layer, we implement the multi-section concept just by etching off small sections of the top metalization on the ridge. The physical mechanism underlying short pulse generation within such system, operating in the 400 - 435nm wavelength range, strongly depends both on the reverse bias applied to the absorber and the forward current in the gain section. Varying the applied reverse bias affects both the absorption and the carrier lifetime in the absorber section through changes in the QW internal field. In consequence we can distinguish between different modes of operation. For moderately long carrier lifetimes the absorber stabilizes relaxation oscillations in the GHz frequency range and self-pulsation occurs, of relatively long duration. With increasing reverse bias, and thus decreasing carrier lifetime, we observe a transition to self-Q-switching. Finally, at large enough negative bias, the carrier life time in the absorber is so short that the laser diode operates in a passive self-mode-locking regime with a repetition rate of 87 GHz and pulse duration of 2 ps for a cavity length of 540 μm.

Citation Download Citation

Katarzyna Holc, Thomas Weig, Wilfried Pletschen, Klaus Köhler, Joachim Wagner, and Ulrich T. Schwarz "Picosecond pulse generation in monolithic GaN-based multi-section laser diodes", Proc. SPIE 8625, Gallium Nitride Materials and Devices VIII, 862515 (4 March 2013); https://doi.org/10.1117/12.2001774

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