Showing papers by "Nick Holonyak published in 2014"
TL;DR: In this article, a high speed 850 nm oxide-confined vertical cavity surface emitting laser with an oxide aperture dimension of ~ 4 μm and a threshold current ITH=0.53 mA at room temperature (20 °C).
Abstract: We have designed and fabricated a high speed 850 nm oxide-confined vertical cavity surface emitting laser with an oxide aperture dimension of ~ 4 μm and a threshold current ITH=0.53 mA at room temperature (20 °C). It demonstrates a modulation bandwidth of 21.2 GHz, and achieves a laser relative intensity noise reaching standard quantum limit 2hν/P0=-154.3 dB/Hz at high bias I/ITH=10. Furthermore, error-free data transmission at 40 Gb/s is obtained at I=6.5 mA which corresponds to an energy/data efficiency of 431 fJ/bit.
52 citations
TL;DR: In this article, the effect of the conduction band energy barrier (ΔEC,B) in the base region of the transistor laser on the minority carrier transport dynamics, recombination lifetime, and frequency response of the device was quantified.
Abstract: Data are presented to quantify the effect of the conduction band energy barrier (ΔEC,B) in the base region of the transistor laser on the minority carrier transport dynamics, recombination lifetime in the base region, and frequency response of the device. A greater ΔEC,B results in lower transistor current gain (β) and higher optical output power, indicating increased carrier confinement and recombination in the base. For a device with ΔEC,B = 41 meV, the measured bias-dependent optical frequency response and subsequent data fitting yield a short recombination lifetime of 30 ps in the base and a small resonance peak of 1.5 dB. A device with ΔEC,B = 82 meV exhibits a longer recombination lifetime of 70 ps and a larger resonance peak of 4 dB.
15 citations
TL;DR: In this article, a low-power operation in a vertical cavity transistor laser via reduced collector offset voltage by placing the emitter contact on the top of four pairs of the GaAs/AlGaAs DBRs was presented.
Abstract: Data are presented on low-power operation in a vertical cavity transistor laser via reduced collector offset voltage by placing the emitter contact on the top of four pairs of the GaAs/AlGaAs DBR to reduce emitter resistance and subsequently depositing 11 SiO2/TiO2 DBR pairs to improve cavity quality. Consequently, the device demonstrates a reduced collector offset voltage of 1.65 V and a low-power dissipation of 6.32 mW under laser operation.
8 citations
TL;DR: In this article, a quantum well transistor laser with a cavity length of 200 μm has been designed and fabricated, and the transistor laser is measured to have a modulation bandwidth f -3dB = 8.1 GHz for IB, = 75 mA (I,B/ITH) with a carrier-photon resonance amplitude (~4.2 dB).
Abstract: A quantum well transistor laser with a cavity length of L = 200 μm has been designed and fabricated. Threshold current at 20°C is determined to be ITH = 36 mA at VCE = 1.5 V from measured transistor laser collector current-voltage (IC-VCE) and optical power-voltage (L-VCE) characteristics. The transistor laser is measured to have a modulation bandwidth f-3dB = 8.1 GHz for IB = 75 mA (IB/ITH ~ 2) with a carrier-photon resonance amplitude (~4.2 dB). At the same bias conditions, the transistor laser demonstrates error-free 13.5-Gb/s data transmission at room temperature.
6 citations
TL;DR: In this article, a 780 nm oxide-confined vertical cavity surface-emitting laser with a threshold current of 0.6 mA at 20 °C is demonstrated, which achieves an 11.2 GHz modulation bandwidth when biased at I=8 mA (I/ITH=13.3), and it achieves the error-free data transmission at 13.5 Gb/s.
Abstract: A 780 nm emission wavelength (far-red) oxide-confined vertical cavity surface-emitting laser with a threshold current of 0.6 mA at 20 °C is demonstrated. The device shows an 11.2 GHz modulation bandwidth when biased at I=8 mA (I/ITH=13.3), and it achieves the error-free data transmission at 13.5 Gb/s.
3 citations
Patent•
26 Aug 2014TL;DR: In this paper, a layered semiconductor structure that includes a substrate, a lower reflector and a semiconductor collector region disposed over the substrate was proposed to produce laser emission from the base region in a vertical resonant optical cavity defined between the lower reflectors and the insulating upper reflector.
Abstract: A method for producing laser emission, including the following steps: providing a layered semiconductor structure that includes a substrate, a lower reflector and a semiconductor collector region disposed over the substrate, a semiconductor base region disposed over the collector region, and a semiconductor emitter region disposed over the base region; providing, in the base region, at least one region exhibiting quantum size effects; depositing collector, base, and emitter electrodes respectively coupled with the collector, base, and emitter regions; disposing an insulating upper reflector over at least a portion of the emitter region; and applying electrical signals with respect to the collector, base, and emitter electrodes to produce laser emission from the base region in a vertical resonant optical cavity defined between the lower reflector and the insulating upper reflector.
2 citations
11 Dec 2014
TL;DR: In this article, the insertion of quantum-wells and tilted charge in the short base of a transistor reduces recombination lifetime below 30 ps which is critical for extending the direct modulation bandwidth of the semiconductor laser towards 200 GHz.
Abstract: The heterojunction bipolar transistor laser, inherently a fast switching device, operates by transporting small minority base charge densities ~1016 cm-3 over nano-scale base thickness (<; 900A) in picoseconds. The insertion of quantum-wells and tilted charge in the short base of a transistor reduces recombination lifetime below 30 ps which is critical for extending the direct modulation bandwidth of the semiconductor laser towards 200 GHz. Three-port operation expands the use of the transistor laser (TL) to optical interconnect and photonic integrated circuits.
1 citations