Definition of critical angle in English:
The angle of incidence beyond which rays of light passing through a denser medium to the surface of a less dense medium are no longer refracted but totally reflected.
- For angles exceeding the critical angle, the refracted waves are evanescent and the reflectivity is very close to unity.
- Compared with the intensity enhancement for total internal reflection (~ 4 times that of the incident light) at the critical angle, the enhancement for SPR can reach up to 20-30 times higher.
- If the beam through m1 is greater than the critical angle, then the refracted beam will be reflected entirely back into m1 (total internal reflection), even though m2 may be transparent!
Definition of critical angle in:
- British & World English dictionary