6 August 2020
CW operation of semi-polar GaN-on-sapphire laser
University of California Santa Barbara (UCSB) in the USA claims the first continuous-wave (CW) electrically driven semi-polar gallium nitride (GaN) blue laser diodes (LDs) at room temperature heteroepitaxially grown on 4-inch sapphire substrate [Haojun Zhang et al, ACS Photonics, vol7, p1662, 2020]. The researchers see their work as “a significant breakthrough in substantially reducing the cost of semi-polar laser diodes and expediting the development of future semi-polar GaN laser diodes and their applications”.
The team believes that topside flip-chip bonding to a high thermally conductive substrate such as silicon carbide could significantly improve laser diode performance and WPE under CW operation.
Study of the optical polarization of the emissions showed it to be almost 100% transverse electric (TE), as opposed to transverse magnetic (TM), at 1100mA injection. This was expected behavior.
Tags: Semi-polar GaN blue laser diodes Blue laser diodes MOCVD GaN
The author Mike Cooke is a freelance technology journalist who has worked in the semiconductor and advanced technology sectors since 1997.