Optics Answers

A laser printer uses a laser with a wavelength of 805nm. What should be the focal length of the lens to focus a collimated laser beam of a diameter of 5mm to obtain a printing resolution of 600 DPI (dots per inch)?

Two thin lenses are in contact and object is placed at 60cm from the lens. It forms a real image at a distance of 35cm from the lens. one of the lenses is converging with the focal.length of 20cm.complete or determine the nature and the total length of the second lens.

 Light is traveling through the two glass slabs as shown below.  

•  850 nm 

Nglass1 = 1.460 
Nglass2 = 1.430 

 (a) What could be the minimum incident angle if total internal reflection has to occur?      

 A beam of vertically polarized linear light is perpendicularly incident on an ideal linear polarizer. Show that if its transmission axis makes an angle of 60° with the vertical only 25% of the irradiance will be transmitted by the polarizer. 

 Write the normalized Jones vectors for each of the following waves, and describe completely the state of polarization of each. (a) 𝐸 ⃗ = 𝐸𝑜 cos(𝑘𝑧 − 𝜔𝑡)𝑥 ̂ − 𝐸𝑜 cos(𝑘𝑧 − 𝜔𝑡)𝑦 ̂    
(b) 𝐸 ⃗ = 𝐸𝑜 sin2π(𝑧/lamda − 𝑣𝑡)𝑥 ̂ + 𝐸𝑜 sin2π( 𝑧/lamda − 𝑣𝑡)𝑦 ̂ 

Explain crest and trough.

What is wavefront.

 Show that the Jones matrix representing a linear polarizer whose transmission axis is at an arbitrary angle 𝜃 with respect to the horizontal is given by

 𝑀(𝜃) =(  𝑐𝑜𝑠²𝜃        𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜃    )          

      𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜃  𝑠𝑖𝑛²𝜃 

The distance between mirror and an object placed in front of it 1.0m If rages of curvature of the mirror 4.0, the image formed will be

In a laser, the lasing levels are the first excited state and the ground state of the

active medium. If the energy of the first excited state is 1.5eV, calculate the

frequency of the laser light