Injection Laser Characteristics

Optical Communications

This set of Optical Communications Multiple Choice Questions & Answers (MCQs) focuses on “Injection Laser Characteristics”.

1. The threshold temperature coefficient for InGaAsP devices is in the range of __________
a) 10-40 K
b) 40-75 K
c) 120-190 K
d) 150-190 K

2. The process where the energy released during the recombination of an electron-hole event getting transferred to another carrier is known as __________
a) Inter-valence bond absorption
b) Auger recombination
c) Carrier leakage effects
d) Exothermic actions

3. Auger recombination can be reduced by using __________
a) Strained MQW structure
b) Strained SQW structure
c) Gain-guided strained structure
d) Strained Quantum dots lasers

.

4. High strain in strained MCQ structure should be incorporated.
a) True
b) False

5. The parameter that prevents carrier from recombination is __________
a) Auger recombination
b) Inter-valence band absorption
c) Carrier leakage
d) Low temperature sensitivity

6. Determine the threshold current density for an AlGaAs injection laser with T0=180k at 30°C.
a) 6.24
b) 9.06
c) 3.08
d) 5.09

7. The phenomenon occurring when the electron and photon population within the structure comes into equilibrium is known as __________
a) Auger recombination
b) Inter-valence band absorption
c) Carrier leakage
d) Relaxation oscillations

8. When a current pulse reaches a laser having parasitic capacitance after the initial delay time, that pulse will __________
a) Have no effect
b) Will get vanished
c) Becomes narrower
d) Gets broader

9. Reducing delay time and ____________ are of high importance for lasers.
a) Auger recombination
b) Inter-valence band absorption
c) Carrier leakage effects
d) Relaxation oscillations

10. Dynamic line-width broadening under the direct modulation of injection current is known as __________
a) Auger recombination
b) Inter-valence band absorption
c) Carrier leakage effects
d) Frequency Chirping

11. A particular characteristic or parameter that occurs during analog transmission of injection lasers is?
a) Noise
b) Mode hopping
c) Carrier leakage effects
d) Frequency Chirping

12. Intensity of output from semiconductor injection lasers leading to optical intensity noise is due to __________
a) Fluctuations in amplitude
b) Mode hopping
c) Carrier leakage effects
d) Frequency Chirping

13. In multimode lasers the optical feedback from unnecessary external reflections affecting stability of frequency and intensity is?
a) Remains unaffected
b) Increased gradually
c) Reduced
d) Gets totally vanished

14. Reduction in the number of modes in multimode fiber increases the mode partition noise.
a) False
b) True

15. The behavior of laser occurring when current is increased above threshold particularly is?
a) Mode hopping
b) Auger recombination
c) Frequency chirping
d) Noise

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