Higher Physics Lab Light & Optics



Exp-1 Determination the wavelength of He-Ne laser using diffraction grating.
Exp-2 Determination the particle size of lycopodium powder.

  • Imported slits.
  • He-Ne laser with in-built power supply.
  • Translucent screen to view the diffraction pattern.
  • Diffraction.
  • Fresnel diffraction.
  • Fraunhofer diffraction
  • Uncertainty of location.
  • Wave-particale.

Shine an expended He-Ne laser beam through a plate dusted with lycopodium powder to construct circular rings on the screen which are nearly spherical and have a very uniform average diameter. The quality of the ring depends on the evenness of dusting.
Wavelength of given laser source of light

n - Order of diffraction
l - Wavelength of laser used in meter
D - Distance between glass plate and screen in meter
xn - Distance between central bright spot and the nth fringe in meter


Cat. No. Item Name Qty
R3891 He-Ne laser 1
C1734 Optical Bench 1
C1734 Screen (30 x 30 cm) 1
SJ095 Microscope slides set of 100 pcs. 1
SL745 Diffraction grating 1
CD555 Slit holder 1
C4737 Slit (Blade) 1
SP124 Measuring tape (3 m) 1
  Lycopodium powder 50gm 1

* Additionally Required

Oscilloscope >40MHz is not supplied with the setup.

Light & Optics Experiments