Student Lecture Series: Dec. 11th

Shereen Hamdy
Dr. Nakamura’s Group
Electrical Engineering

​Efficient Tunnel Junction Contacts for High-Power III-Nitride Edge-Emitting Laser Diodes

We demonstrate III-Nitride edge-emitting laser diodes (LDs) with tunnel junction contacts grown by MBE. Lower threshold current densities were observed in LDs with MBE-grown tunnel junctions than in control LDs with ITO contacts. LDs with tunnel junction contacts grown by MOCVD were also demonstrated. These LDs underwent a p-GaN activation scheme utilizing lateral diffusion of hydrogen through LD ridge sidewalls. Secondary ion mass spectroscopy measurements of the tunnel junction [Si] and [Mg] profiles were conducted to further investigate the results.

​Brandon Isaac
Dr. Klamkin’s Group
Materials

​InP Photonic Integrated Circuit Transmitter with Integrated Linewidth Narrowing for Laser Communications and Sensing

​An integrated solution for reducing the linewidth of widely tunable semiconductor diode lasers is presented.  Reducing the linewidth of tunable diode lasers enables lower cost, size, weight, and power (CSWaP) for many applications including LiDAR, sensing, and communication.  I will discuss the operating principles of the system, and show how it is realized in a photonic integrated circuit with characterization of the  components.  Utilizing this circuit to enable a photonic integrated transceiver for frequency modulated continuous wave LiDAR  is discussed.

Tuesday, Dec. 11th at 12:00 PM in Elings 3001
Pizza will be provided!