| 摘要 |
An optical arrangement, method and measurement system are disclosed. The arrangement includes a first input 120 to receive a first beam 101 from a frequency swept laser 180, a second input 130 to receive a second beam 102 from a fixed frequency pump laser source 190. A non-linear optical artefact 140 receives and intermodulates the first and second beams to generate a third beam 103, the third being an inverted copy of the first beam mirrored relative to the fixed frequency of the pump laser source. Preferably, the first and second beams 101,102 are removed at a filter 160 before the third beam is output at 150. A selective combining element outputs the first and third beams. The non-linear artefact or one or both of the lasers is selected or configured such that the optical frequency separation of the first and second beams satisfies the coherence length condition of the non-linear artefact 140. Examples of possible non-linear artefacts may be semiconductor optical amplifiers (SOAs), non-linear fibres and non-linear waveguides. |
