Lasers for Holography

1. Basic principles:
Holography is a technology that uses the principles of interference and diffraction to record and reproduce real three-dimensional images of objects.
Holography is divided into two processes: recording and reproduction. Holography is a two-step lensless imaging method that uses the principle of "interference recording and diffraction reproduction".
The recording process is to superimpose the reference light and the light reflected from the object on the holographic dry plate to produce interference fringes. After the dry plate is processed in a dark room, diffraction is used to reproduce the interference pattern on the photosensitive film to be exactly the same as the original object. picture.
2. Optional wavelength and power of Laser light source
Common laser wavelengths: 457nm, 473nm, 532nm, 561nm, 639nm, 671nm
Laser type: Single Longitudinal Mode Laser
Laser power: common power (100mw/200mw/300mw/500mw/1W/2W/3W......)
Laser parameter requirements:
The coherence length should be long, the polarization ratio should be as high as possible (>100:1), the wavelength stability should be good, and there should be no mode hopping.
Try to choose water-cooling. The vibration of the air-cooled fan will cause the light spot to jitter and affect the effect of holographic photography.
For full-color holography, the divergence angle and spot consistency of the red, green and blue lights need to be better.