Advanced Middle-UV Coherent Optical Sources
Abstract
We have developed MOCVD growth technologies for III-N deep-UV lasers on two different growth systems: the "standard" Thomas-Swan 6x2 Close-Coupled Showerhead MOCVD reactor using AlGaN-AlN growth conditions at ~1150 deg C, and one new high-temperature AIXTRON 3x2 Close-Coupled Showerhead MOCVD system operating at up to ~1300 deg C, to allow us to explore "higher temperature" growth regimes. We have exploited advanced high-resolution materials growth technologies, to characterize the III-N wide-bandgap materials. We have developed the most complete and advanced III-N device simulation tool and have utilized it to optimize the optical and electrical performance of deep-UV laser diodes at ~250nm. We have developed and exercised the required III-N UV laser device processing, wafer thinning, facet cleaving, facet coating, and optical characterization techniques and exploited these processes to demonstrate optically pumped pulsed UV lasers at lambda < 250nm with thresholds as low as ~297 kW/sq cm for lasers at lambda = 245.3 nm without facet coatings. Additional studies of optically pumped lasers with one facet coated have shown 300K lasing at 249nm and threshold of 230 kW/sq cm. Optically pumped lasers at 249 nm have also been demonstrated with thresholds as low as 180kW/sq cm for laser bars with facet coatings on both facets. Developed n-type and p-type doping for AlGaN-based cladding layers for deep-UV lasers. The testing of our first complete UV laser p-n junction diode structures grown on AlN substrates was completed and the I-V characteristics and EL spectra were measured. However, no laser operation was observed at 300K under pulsed conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 15, 2013
- Accession Number
- ADA593936
Entities
People
- Jae-hyun Rou
- M. M. Satter
- P. D. Yoder
- Russell D. Dupuis
- Shyh-chiang Shen
- Theeradetch Detchprohm
- Tsung-ting Kao
- Xiao-hang Li
- Yuh-shiuan Liu
- Zachary Lochner
Organizations
- Georgia Tech