We successfully fabricated nitride-based light-emitting diodes (LEDs) with 22 undercut sidewalls. The 22 etching undercut sidewalls were achieved by controllable inductively coupled plasma reactive ion etching. With a 20-mA current injection, the output powers of the LED with 22 undercut sidewalls and standard LED were 5.1 and 3 mW, respectively-a factor of 1.7 times enhancement. It was found that such undercut sidewalls could enhance the probability of escaping the photons outside from the LED in the near horizontal and in-plane directions. This simple and controllable method is beneficial to fabricate brighter LEDs.Index Terms-Etching profile, GaN, light-emitting diode (LED), light extraction efficiency.
Stable bound soliton laser mode-locking is experimentally demonstrated in an environmentally stable hybrid mode-locked Er-doped fiber laser without incorporating (equivalent) nonlinear saturable absorption effects. The laser is with a sigma-type cavity and exhibits a higher threshold for single to bound soliton mode-locking state transition. A nonlinear eigenstate analysis based on the master equation model and the concept of steady state lasing gain is developed to more physically explain the observed mode-locking state transition phenomena.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.