Q. Replacing Sn with Eu, Cd or Ge in some _________________ the band gap.

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Q. Lasing obtained in __________ when 191 mW of pump light at a wavelength of 0.477 μm is launched into laser.

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Q. The thulium doped fiber laser when pumped with alexandrite laser output at 0.786 μm, the laser emits at ___________

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Q. The diode-cladding-pumped Erbium praseodymium-doped fluoride device operates at wavelength.

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Q. A technique based on inter-sub band transition is known as ___________

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Q. In a QC laser, a same electron can emit number of photons.

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Q. The phenomenon resulting in the electrons to jump from one state to another each time emitting of photon is known as ___________

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Q. A QC laser is sometimes referred as ___________

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Q. In QC lasers, it is possible to obtain different output signal wavelengths. This can be achieved by ___________

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Q. QC lasers ______________ the performance characteristics.

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Q. An MQW cascaded laser is more advantageous because of ___________

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Q. The absence of _______________ in LEDs limits the internal quantum efficiency.

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Q. The excess density of electrons Δn and holes Δpin an LED is ____________

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Q. The hole concentration in extrinsic materials is _________ electron concentration.

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Q. The carrier recombination lifetime becomes majority or injected carrier lifetime.

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Q. In a junction diode, an equilibrium condition occurs when ____________

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Q. Determine the total carrier recombination lifetime of a double heterojunction LED where the radioactive and nonradioactive recombination lifetime of minority carriers in active region are 70 ns and 100 ns respectively.

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Q. Determine the internal quantum efficiency generated within a device when it has a radiative recombination lifetime of 80 ns and total carrier recombination lifetime of 40 ns.

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Q. Compute power internally generated within a double-heterojunction LED if it has internal quantum efficiency of 64.5 % and drive current of 40 mA with a peak emission wavelength of 0.82 μm.

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Q. The Lambertian intensity distribution __________ the external power efficiency by some percent.

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