The concept of experiment is determining the wavelength of semiconductor laser and minimal voltage of barrier both,. The screen is installed in (50-70) cm far from gitter. To provide perpenicularity of screen and ray, the units should be configured in the board’s corner. A high diffractio order is observed if a gitter of small number of strokes is utilized. The gitter must be installed perpendicularly to ray path. The optical set is adjusted by gitter reflection or minimal distance between diffraction orders. Voltage pulsing leads to the decreasing the barrier voltage registered.
The results (using non-expensive laser pointer):
Wavelength, 670 nm
Lighting voltage, 1.8 V (both for crystal and outlets with 1% mistake)
Laser module taken from the "Wave optics" demonstration set is almost the same but its wavelength is 685 nm. The possible reason is rather bad gitter which has a mistake about 2% of number of strokes due to 13 nm respectively.
Dioes stop lighting at 1.5 V voltage only. The possibility of seeing a stain in darkness was considered.
Planck’s constant, 6.43*10-34 J*s
Tabulated value, 6.62*10-34 J*s To carry out the experiments you will need: Demonstrational meter |