4.3 GHz Optical Bandwidth Light Emitting Transistor
- 詳細技術說明
- The hetero-junction bipolar light emitting transistor (HBLET), which uses a high-speed hetero-junction bipolar transistor (HBT) structure, could potentially function as a light source with speeds exceeding ten’s of GHz.
- *Abstract
-
Semiconductor light emitting diodes (LEDs) and lasers using direct gap III-V materials, and electron-hole injection and recombination, have over the years led to numerous applications in display and light-wave communications. While semiconductor lasers typically dominate long-distance communications links, fast spontaneous light-wave can be an attractive solution for short range optical data communications and optical interconnections as their threshold-less operation, high fabrication yield and reduced driver and feedback control complexity significantly reduce the overall cost, form factor and power consumption of transmitters.
However, the fastest spontaneous light source shown to date (a light emitting diode) employs p-doping as high as 7X1019 cm-3 to achieve a bandwidth of 1.7 GHz, at the cost of reduced internal quantum efficiency to 10% or less. In practice, higher efficiency spontaneous devices such as LEDs or RCLEDs operate with bandwidths that are less than 1 GHz, restricting actual commercial application of spontaneous light transmitters (LEDs and RCLEDs) to less than 1 Gbits/s.
With this technology an improved 4.3 GHz optical microwave performance of a three-port light emitting transistor is achieved.
DESCRIPTION/DETAILS
The hetero-junction bipolar light emitting transistor (HBLET), which uses a high-speed hetero-junction bipolar transistor (HBT) structure, could potentially function as a light source with speeds exceeding ten’s of GHz. The room temperature, continuous wave operation of a transistor laser further demonstrates that a practical radiative recombination center (i.e. undoped quantum well) can be incorporated in the heavily doped base region of a HBLET. In practice, despite the high intrinsic speed of the HBT, the microwave performance of an HBLET is severely limited by parasitic capacitances, partly owing to the need to include light extraction features (such as oxide apertures) not present in traditional high speed HBT devices.
With this technology an improved 4.3 GHz optical microwave performance of a three-port light emitting transistor is achieved which significantly reduces the overall parasitic capacitances. Also, the three-terminal nature of the light emitting transistor offers two input-output configurations for electrical-to-optical output conversion, e.g., via the common-collector BC- and EC-input ports, each with its own unique advantages.
APPLICATIONS
Together with the advantages of higher yield, reduced complexity and three-terminal high-speed modulation capabilities as both a transistor (amplifier and switch) and electrical-to-optical convertor, the HBLET could be an attractive solution for short range optical data communications, and has significant implications for the development of high-speed semiconductor lasers and integrated optoelectronics.
BENEFITS
This hetero-junction bipolar light emitting transistor (HBLET) technology indicates that spontaneous recombination can be fast and higher modulation speeds are possible by further reducing the undesirable parasitic. In addition, due to the absence of the relaxation oscillations typically observed in laser devices and the lesser attenuation slope, an HBLET could potentially be deployed at data rates much higher than 4.3 Gb/s.
Together with the advantages of higher yield, reduced complexity and three-terminal high-speed modulation capabilities as both a transistor (amplifier and switch) and electrical-to-optical convertor, the HBLET could be an attractive solution for short range optical data communications, and has significant implications for the development of high-speed semiconductor lasers and integrated optoelectronics.
For more information about this technology, please contact the University of Illinois at Urbana-Champaign Office of Technology Management at otm@illinois.edu.
- *IP Issue Date
- None
- *IP Type
- Utility
- 國家
- United States
- 申請號碼
- 8179937
- 國家/地區
- 美國
