| 摘要 |
PROBLEM TO BE SOLVED: To achieve light sampling for obtaining a clean light sample. SOLUTION: The frequency of a probe pulse signal from a probe pulse signal source (401) is doubled by a frequency double multiplier (403) to obtain intermediate second harmonic output including a second harmonic probe pulse signal. The intermediate second harmonic output is filtered by a light filter (404), a background noise is removed, the filtered intermediate second harmonic probe pulse signal is mixed with a user input light signal by mixers (408, 413) for obtaining a third harmonic proximity signal, and repairing is made by processor means (411, 414, 416), thus obtaining a sample of user input light signal where the background noise has been reduced. |
