Polarization by half-wave plate

Item Code: SK073

Principle and Working :

A wave plate or retarder is an optical device that alters the polarization state of a light beam traveling through it.

In the present setup, the diode laser light passes through polarizer to produce linearly polarized light. It then passes through the half wave plate λ/2. The λ/2 plate produces linear polarised light. For different angles of the λ/2 plate with respect to optic axis only the polarisation plane changes. The maximum and minimum are not changed which can be investigated with the analyser over the range -90 to +90 degrees.




  • Class I diode laser with output power 0.4 - 0.8 mV
  • Saddle can hold rod from 8 to 15mm.
  • Precise measurement using Data logger & light sensor with Graph analyser software
  • Heavy, rigid and stable Triangular Optical bench (made of Al extrusion)
  • Height and level adjustment screws (made of SS)
  • Data logger can collect 1,00,000 samples per sec.

Learning Objectives/experiments

  • To measure the light intensity of plane polarised light as a function of the analyzer position.
  • To study the polarization of light by half wave plate
  • Produce plane polarised light using half wave plate
  • Light sensor : Range 0 - 600 Lx, resolution 0.15 Lx Range 0 - 6000 Lx,resolution 1.5 Lx Range 0 - 150K Lx, resolution 37 Lx
  • Accuracy : + 4% over entire range
  • Dataloger : Up to 100K SPS,
  • Transmission : from 0 to 100 %, resolution 0.1%memory capacity 800K sample,
  • Li polymer rechargeable battery, 6 in-built sensor, 4 ext. sensor port (60+ sensor available), connectivity port micro USB, 90.2 x 90.2 x 20mm(LxWxH), 120gm
  • Diode laser : Wavelength 635nm, Operating voltage 5V DC, Optical power 0.4-0.8mW, Class II,
  • Optical bench : Al exclusion, L = 1 mtr., Triangular shape with end stop, 4 point levelling (SS screw)
  • Polarizer : Angle (0 + 90°), LC 1°, Aperture 21mm, Frame 130mm, Rod 10 mm
  • Half wave plate : Angle (0 + 90°), LC 1°, Aperture 21mm, Frame 130mm, Rod 10mm
  • Fixed slider : Al Extrusion, Base width 50mm, H 115mm
  • 1 Optical bench Triangular
  • 1 Transverse saddle
  • 1 Diode laser with adapter
  • 2 Polarizer / Analyzer
  • 1 Half wave plate
  • 1 Light sensor
  • 1 Data logger
  • 1 Light sensor holder
  • 1 Fixed saddle
  • 1 Software CD (MiLAB)
  • 1 Sensor cable (mini USB)