This work reports comprehensive modeling of photocurrent spectra generated by an InGaN/InGaN disk-in-wire photodiode based on the effective bond-orbital model. The photocurrent spectra contributed by both single-photon absorption and two-photon absorption are calculated. The physical mechanisms for the observed prominent peaks are identified and investigated.
Single transverse mode operation in vertical-cavity surface-emitting lasers (VCSELs) is desired over multimode operation in a number of applications. This work presents a method of achieving single-mode operation by depositing an annulus-shaped semiconductor coating atop an 850 nm oxide-confined VCSEL to modify the standing wave of the optical field in the laser cavity. The devices are benchmarked for singlemode performance as well as optical output power via optical spectra and light-current-voltage (LIV) measurements respectively.
The promise of silicon integrated circuits with their electronic or photonic functionality enhanced via heterogeneous integration has motivated significant work in understanding and overcoming the barriers to realizing such an IC. Additional hurdles must be overcome when integrating devices that are highly sensitive to temperature variation such as semiconductor lasers. Challenges in the heterogeneous integration process will be reviewed, and approaches for heterogeneous integration that have the potential to enable silicon ICs with enhanced functionality will be discussed in the context of integrated photonic systems.
The transistor-injected quantum cascade laser (TI-QCL) is a novel design for a mid-wave infrared (MWIR) laser that seeks to overcome some of the primary limitations of standard quantum cascade lasers (QCLs). By growing the active cascade region within the base-collector junction of an npn heterojunction bipolar transistor (HBT), independent control of the injection current and active region bias is achievable through the emitter current and base-collector reverse bias respectively. The active region bias is important to properly align the lasing states and to control the lasing wavelength. Physical design limitations of the TI-QCL and their effects on the fabrication process of samples is presented. In order to characterize device performance and validate fabrication improvements, InP-based device samples designed for λ= 7.3 µm emission are fabricated. Preliminary characterization results are shown in the form of diode measurements to validate the HBT electrical operation of the TI-QCL which is necessary to realize the optical benefits of the device.
“VCSELs are a type of device that are seeing broad use in a growing number of applications,” said Dallesasse. “They are being looked at for use in self-driving cars that utilize LIDAR, and are already extensively used in the fiber optic networks of large data centers.”
“We’re specifically looking at ways of improving the optical beam that comes out of the VCSEL,” said Dallesasse. “When you have a device like a VCSEL, the optical modes can be thought of as the light patterns on the surface. In order for you to utilize patterns, it’s desirable to be able to control those light patterns.”
The Advanced Semiconductor Device and Integration Group was awarded the CS MANTECH 2018 Best Student Paper Award by Patrick Su, Fu-Chen (Alex) Hsiao, Tommy O’Brien and Professor Dallesasse on Controlling Impurity-Induced Disordering via Mask Strain for High-Performance VCSELs.
CS MANTECH 2018 Best Student Paper Award Link Here!
The Advanced Semiconductor Device and Integration Group is proud to share a recent publication by Patrick Su, Fu-Chen (Alex) Hsiao, Tommy O’Brien and Professor Dallesasse on demonstrating a novel method of controlling impurity-induce disordering apertures via Mask Strain that can be applied to wafer-scale manufacturing of high-power single-mode VCSELs.
IEEE Transactions in Semiconductor Manufacturing Article Here!
Patrick Su and Fu-Chen (Alex) Hsiao were awarded the II-VI Foundation Block-Gift award aiming to develop the professional knowledge and experience of Ph.D. candidates. This project is focused on developing single-mode high-power Vertical-Cavity Surface-Emitting Lasers (VCSELs). They are grateful for the support and opportunity provided by the II-VI Foundation.
At the International Compound Semiconductor Manufacturing Technology (CS MANTECH) 2018, John Carlson and Patrick Su were honored with the Best Poster Award on a method of integrating III-V semiconductor material suitable for lasers onto silicon which is used for CMOS electronics. John has demonstrated a novel demonstration of epitaxial bonding and transfer for heterogeneous integration of electron-photonic circuitry.
More details can be found in this link.
The Advanced Semiconductor Device and Integration Group is proud to share a recent publication by Kanuo Chen, Fu-Chen (Alex) Hsiao, Brittany Joy, and Professor Dallesasse on demonstrating the ability to control radiative base recombination in a quantum-cascade light emitting transistor that shows performance benefits of a transistor-injected QCL over conventional QCL devices.
Applied Physics B Article Link
