Publications by    
Page 1  (4 Items)

1.  
Quantum cascade lasers that emit more light than heat
Quantum cascade lasers that emit more light than heat
Y. Bai, S. Slivken, S. Kuboya, S.R. Darvish and M. Razeghi
Nature Photonics, February 2010, Vol. 4, p. 99-102-- February 1, 2010
For any semiconductor lasers, the wall plug efficiency, that is, the portion of the injected electrical energy that can be converted into output optical energy, is one of the most important figures of merit. A device with a higher wall plug efficiency has a lower power demand and prolonged device lifetime due to its reduced self-heating. Since its invention, the power performance of the quantum cascade laser has improved tremendously. However, although the internal quantum efficiency can be engineered to be greater than 80% at low temperatures, the wall plug efficiency of a quantum cascade laser has never been demonstrated above 50% at any temperature. The best wall plug efficiency reported to date is 36% at 120 K. Here, we overcome the limiting factors using a single-well injector design and demonstrate 53% wall plug efficiency at 40 K with an emitting wavelength of 5 µm. In other words, we demonstrate a quantum cascade laser that produces more light than heat. reprint
 
2.  
Recent performance records for mid-IR quantum cascade lasers
Recent performance records for mid-IR quantum cascade lasers
M. Razeghi; Y. Bai; S. Slivken; S. Kuboya; S.R. Darvish
Terahertz and Mid Infrared Radiation: Basic Research and Practical Applications, 2009. TERA-MIR International Workshop [5379656], (2009) -- November 9, 2009
The wall plug efficiency of the mid-infrared quantum cascade laser in room temperature continuous wave operation is brought to 17%. Peak output power from a broad area (400 μm x 3 mm) device gives 120 W output power in pulsed mode operation at room temperature. Using a single-well-injector design, specifically made for low temperature operation, a record wall plug efficiency of 53% is demonstrated at 40 K. reprint
 
3.  
Gain-length scaling in quantum dot/quantum well infrared photodetectors
Gain-length scaling in quantum dot/quantum well infrared photodetectors
T. Yamanaka, B. Movaghar, S. Tsao, S. Kuboya, A. Myzaferi and M. Razeghi
Virtual Journal of Nanoscale Science & Technology-- September 14, 2009reprint
 
4.  
Gain-length scaling in quantum dot/quantum well infrared photodetectors
Gain-length scaling in quantum dot/quantum well infrared photodetectors
T. Yamanaka, B. Movaghar, S. Tsao, S. Kuboya, A. Myzaferi and M. Razeghi
Applied Physics Letters, Vol. 95, No. 9-- August 31, 2009
The gain in quantum dot/quantum well infrared photodetectors is investigated. The scaling of the gain with device length has been analyzed, and the behavior agrees with the previously proposed model. We conclude that we understand the gain in the low bias region, but in the high field region, discrepancies remain. An extension of the gain model is presented to cover the very high electric field region. The high field data are compared to the extended model and discussed. reprint
 

Page 1  (4 Items)