Reflection Phase Shifts

Physics Assignment Help Online

Reflection Phase Shifts

Refraction at an interface never causes a phase change- but reflection can, depending on the indexes of refraction on the two sides of the interface.  shows what happens when reflection causes a phase change, using as an example pulses on  a denser string (along which pulse travel is relatively slow  and a lighter string along which pulse travel is relatively fast). When a pulse traveling relatively slowly along the denser string in -13a reaches the interface with the lighter string, the pulse is partially transmitted and partially reflected, with no change in orientation. For light, this situation corresponds to the incident wave traveling in the medium of greater index of refraction n (recall that greater n means slower speed). In that case, the wave that is reflected at the interface does not undergo a change in phase; that is, its reflection phase shift is  zero.When a pulse traveling more quickly along the lighter string in Fig. 36-13b  reaches the interface with the denser string, the pulse is again partially transmitted and partially reflected. The transmitted pulse again has the same orientation as the incident pulse, but now the reflected pulse is inverted. For a sinusoidal wave, such  an inversion involves a phase change of 1T rad, or half a wavelength. For light, this situation corresponds to the incident wave traveling in the medium of lesser index of refraction (with greater speed). In that case, the wave that is reflected at the interface undergoes a phase shift of 1T rad, or half a wavelength. We can summarize these results for light in terms of the index of refraction of results

 

 

 

Other assignments related to

Reflection Phase Shifts