Question

1. A Fabry-Perot etalon (or resonator) is formed by two mirrors in air. The distance between mirrors is 1.25 (mm), and the reflectance of each mirror is 0.92.

What is the mode of the etalon that is closest to the wavelength of 1.55 (µm)?

2. What is the separation of the modes in the etalon?

3. The finesse, F, of the etalon is defined as the ratio of mode separation to spectral width of each mode, and depends on the mirror reflectances, R, as:

F=π√R/(1-R)

Find the finesse of this etalon {give your answer to 4 significant digits, this is a unitless quantity}.

4. What is the spectral width of each mode, δVm (in GHz)

5. What is the quality factor for this resonator?

Answer 1