This set of Optical Communications Multiple Choice Questions & Answers (MCQs) focuses on “Non – Semiconductor Lasers”.
1. ____________________ lasers are presently the major laser source for optical fiber communications.
2. In Nd: YAG lasers, the maximum doping levels of neodymium is ____________
a) 0.5 %
b) 1.5 %
c) 1.8 %
d) 2 %
3. Which of the following is not a property of Nd: YAG laser that enables its use as an optical fiber communication source?
a) Single mode operation
b) Narrow line-width
c) Long lifetime
d) Semiconductors and integrated circuits
4. The Nd: YAG laser has a narrow line-width which is ________________
a) < 0.01 nm
b) > 0.01 nm
c) > 1 mm
d) > 1.6 mm
5. The strongest pumping bands is a four level system of Nd: YAG laser at wavelength of range_________________
a) 0.25 and 0.56 nm
b) 0.75 and 0.81 nm
c) 0.12 and 0.23 nm
d) 1 and 2 nm
6. The Nd: YAG laser is costlier than earth-doped glass fiber laser.
7. It is a resonant cavity formed by two parallel reflecting mirrors separated by a mirror separated by a medium such as air or gas is?
a) Optical cavity
b) Wheatstone’s bridge
d) Fabry-perot resonator
8. In a three level system, the threshold power decreases inversely with the length of the fiber gain medium.
9. Which of the following co-dopant is not employed by neodymium and erbium doped silica fiber lasers?
a) Phosphorus pent oxide
10. Dopants levels in glass fiber lasers are generally ___________
c) Same as that of GRIN rod lens laser
d) Same as that of semiconductor laser
11. _______________ fibers include addition of lead fluoride to the core glass in order to raise the relative refractive index.
12. The lasing output of the basic Fabry-perot cavity fiber is restricted to between ____________
a) 1 and 2 nm
b) 5 and 10 nm
c) 3 and 6 nm
d) 15 and 30 nm
13. In Fabry-perot laser, the lower threshold is obtained by ___________
a) Increasing the refractive index
b) Decreasing the refractive index
c) Reducing the slope efficiency
d) Increasing the slope efficiency
14. When did the non-semiconductor laser developed?
15. Y3Al5 O12 is a molecular formula for _____________
a) Ytterbium aluminate
b) Yttrium oxide
c) Ytterbium oxy-aluminate
d) Yttrium-aluminum garnet