Saved Bookmarks
| 1. |
Give the justification for validity of ray optics. |
|
Answer» Solution :The distance much smaller then `Z_F`, the spreading DUE to diffraction is smaller compared to the size of the beam. When the distance is approximately `Z_F`, and much more than `Z_F`, the spreading due to diffraction DOMINATES over that due to RAY OPTICS (size of the APERATURE (a)] `Z=(a^(2))/(lambda)` From this equation ray optics is valid in the limit of wave length tending to zero. |
|