Question

the Half width of the jain profile of helium ne laser materials is 2 x 10-³ nm the length of the cavity is 30 cm and the emission wavelength length of he - ne laser is 6328A⁰, how many longitudinal modes can be excited​

Answer 1

the Half width of the jain profile of helium ne laser materials is 2 x 10-³ nm the length of the cavity is 30 cm and the emission wavelength length of he - ne laser is 6328A⁰, how many longitudinal modes can be excited

answer hope it helps u:

about 10-30 cm

The distance over which the waveform remains similar to a sine-wave is called the coherence-length of the beam, Lc, and it is typically about 10-30 cm for commercial He-Ne lasers.