1. A Raman amplifier uses intrinsic properties of _____ fibers to obtain signal amplification.

2. The physical property behind DRAs is called _____.

3. ___________ occurs when the pump photon gives up its energy to create a new photon at the signal wavelength, plus some residual energy, which is absorbed as phonons.

4. Raman amplification potentially can be achieved in every region of the transmission window of the optical transmission fiber.

5. The Raman pump wave can be conveniently placed at the ________ locations.

6. Despite the many advantages of Raman amplification, there can be some degradation effects.

7. Raman amplifiers are ____________ to design than doped-fiber amplifiers, as the existing transmission fiber can be used as a medium if properly pumped.

8. When building distributed Raman amplifiers, designers must use backward pumping with respect to signal propagation.

9. Further down the fiber, when the power of the low-wavelength pumps is reduced due to energy transfer to high wavelengths and fiber attenuation, the effect of pump-to-pump amplification is reduced.

10. It is not necessary to include nonlinear propagation effects in the system design process when deciding on optimum signal and pump powers.