When the refractive index $$\mu $$ of the active medium changes by $${\Delta \mu }$$  in a laser resonator of length L, the change in the spectral spacing between the longitudinal modes of the laser is (c is the speed of light in free space)

When the refractive index $$\mu $$ of the active medium changes by $${\Delta \mu }$$  in a laser resonator of length L, the change in the spectral spacing between the longitudinal modes of the laser is (c is the speed of light in free space) Correct Answer $$\frac{c}{{2L}}\frac{{\Delta \mu }}{{\mu \left( {\mu + \Delta \mu } \right)}}$$

Bissoy MCQ

Related Questions

Choose the correct relation for a combination of two prisms to be achromatic. (Where for the first prism: μv = refractive index of the medium in violet light, μr = refractive index of the medium in red light A = angle of the prism; For the second prism: μ′v = refractive index of the medium in violet light, μ′r = refractive index of the medium in red light, A’ = angle of prism.)
There are two medium L1 and L2 of refractive index n1 and n2 respectively (n2  > n1 > 1). In which of the following condition the total internal reflection may occur: a) When the light travel from medium L1 to medium L2. b) When the light travels from medium L2 to medium L1. c) When the light travel from medium L1 to air. d) When the light travels from air to medium L2. Which of the following statement is correct?
Consider the following remarks pertaining to the irrotational flow: 1. The Laplace equation of stream function \(\frac{{{\delta ^2}{\rm{\Psi }}}}{{\delta {x^2}}} + \frac{{{\delta ^2}{\rm{\Psi }}}}{{\delta {y^2}}} = 0\) must be satisfied for the flow to be potential. 2. The Laplace equation for the velocity potential \(\frac{{{\delta ^2}{\rm{\varphi }}}}{{\delta {x^2}}} + \frac{{{\delta ^2}{\rm{\varphi }}}}{{\delta {y^2}}} = 0\) must be satisfied to fulfil the orate . of mass conservation i.e continuity equation.. Which of the above statements is/are correct?
When light passes from air to glass it experience change in refractive index. and due to change in refractive index the wavelength of light changes and hence speed.
A crown glass prism with refractive index 6° is to be achromatized for red and blue color light with flint glass prism. What will be the angle of flint glass prism? (µr = 1.513, µr‘ = 1.645, µ2 = 1.523 and µ2‘ = 1.665, Where µr and µ2 are refractive indices of red and blue light respectively whereas, µr‘ and µ2‘ are refractive indices of red and blue light respectively for flint glass.)
Which of the following gives the correct representation of the refractive index when light is traveling from air (medium 1) to crown glass (medium 2)? (Given: speed of light in air = 3 x 108 m/s, speed of light in crown glass = 1.97 x 108 m/s)
A ray of light travels from a medium of refractive index m1 to a medium of refractive index m2. If “i” and “r” are the angle of incidence and refraction, then what is sin(i)/sin(r)?
A 4 km optical link consists of multimode step index fiber with core refractive index of 1.3 and a relative refractive index difference of 1%. Find the delay difference between the slowest and fastest modes at the fiber output.
All the forms of matter except gases emit electromagnetic radiation continuously. The gases which electrically or thermally excited emit a certain wavelength only, then which of the following is/are true about the process (i) The spacing between the atoms in the other forms of matter is high than in gas (ii) The spacing between the atoms in gases is high than the other forms of matter (iii) The energy of the emitted radiation depends on the spacing between the atoms (iv) The wavelength of the emitted radiation depends on the spacing between the atoms 
What is the distance covered by boat N upstream in 5 hours? Which of the following option is sufficient alone to find the answer? A) Boat M is travelling downstream with 20% more downstream speed of boat N. Speed of boat M in still water is 10% more than the speed of boat N in still water. B) Boat M and Boat N are travelling downstream with speed 33 km/hr and 40 km/hr respectively and speed of boat M is still water is 2 times the speed of stream. C) Speed of boat M in still water is 6 km/hr less then speed of boat N in still water and speed of stream is 10 km/hr. D) Speed of stream is ½ times the speed of boat N in still water and downstream speed of boat M is 44 km/hr. E) Speed of stream is 10 km/hr and ratio of upstream speed of boat M and boat N is 3 : 2 respectively.