To improve a judgement of a physical condition of an optical element by a measurement of a response signal.
At least two measurements which continue timewise are performed. Therefore, a first light signal (S1) is sent to the optical element (10), a first optical property (λ) of the first light signal changes with a first time function. A second optical property (P(λ)) of a first response signal (R1) returned from the optical element (10) is measured over a certain period. A first result function (P1) of the second optical property of the first response signal is established on the first optical property of the first light signal. A second light signal (S2) is sent to the optical element (10), the first optical property (λ) of the above signal changes with a second time function which is different from the first time function. The second optical property corresponding to a second response signal (R2) is measured, a second result function (P2) of the second optical property of the response signal is established on the first optical property of the transferred light signal. The physical condition of the optical element is obtained by a comparison the first result function with the second result function.
| US4632551A | 1986-12-30 | |||
| US4632551A | 1986-12-30 |
Takahiko Mizobe
Kiyoharu Nishiyama