Q. The important parameter for exciting an electron with energy required from valence band to conduction band is?

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Q. __________ is less than or unity for photo detectors.

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Q. There must be improvement in __________ of an optical fiber communication system.

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Q. The _____________ is photosensitive to act as light gathering element.

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Q. A large secondary current _________________ in n-p-n InGaAs phototransistor is achieved.

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Q. _______ emitter-base and collector-base junction capacitances is achieved by use of hetero-structure along with _________ base resistance.

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Q. A ________ is created by hetero-junction at collector-base junction.

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Q. Phototransistors based on hetero-junction using _________ material are known as waveguide phototransistors.

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Q. A phototransistor has collector current of 18 mA, incident optical power of 128 μW with a wavelength of 1.24 μm. Determine an optical gain.

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Q. For a phototransistor having gain of 116.5, wavelength of 1.28 μm, optical power 123 μW. Determine collector current.

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Q. The detection mechanism in the ____________ photo-detector includes inter sub-band transitions.

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Q. Which of the following is the difference between the n-p-n and conventional bipolar transistor?

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Q. The n-p-n hetero-junction phototransistor is grown using ______________

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Q. The _____________ at emitter-base junction gives good emitter base injection efficiency.

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Q. Waveguide phototransistors utilize a ___________ waveguide layer under the _________ transistor region.

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Q. What is the main benefit of the waveguide structure over conventional hetero-junction phototransistor?

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Q. Waveguide structure provides high quantum efficiency.

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Q. Metal-semiconductor-metal (MSM) photo-detectors are photoconductive detectors.

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