Optical path

Optical path (OP) is the trajectory that a light ray follows as it propagates through an optical medium. The geometrical optical-path length or simply geometrical path length (GPD) is the length of a segment in a given OP, i.e., the Euclidean distance integrated along a ray between any two points. The mechanical length of an optical device can be reduced to less than the GPD by using folded optics. The optical path length in a homogeneous medium is the GPD multiplied by the refractive index of the medium.

Factors affecting optical path

Path of light in medium, or between two media is affected by the following:

• Reflection
  • Total internal reflection
• Refraction
• Dispersion of light
• Absorption

Simple materials used

• Lenses
• Prisms
• Mirrors
• Transparent materials (e.g. optical filters)
• Translucent materials (e.g. frosted glass)
• Opaque materials

References

1. Optical path length
2. Interferometry
3. Optical depth
4. Differential interference contrast microscopy
5. Optical glass
6. Optical DPSK demodulator
7. Ray (optics)
8. Optical tweezers
9. Refractive index
10. Optical disc drive
11. Path length
12. Nonimaging optics
13. Catadioptric system
14. Thin-film interference
15. Optical cavity
16. Mach–Zehnder interferometer
17. Hamiltonian optics
18. Fourier-transform infrared spectroscopy
19. Photomask
20. Multipath propagation