| 摘要 |
A beamsplitter 100 for splitting an input beam 10 of radiation into at least one first 20a and second 20b output beam. The beamsplitter has first 110 and second 120 portions for generating first and second output beams; wherein the first portion has parallel front 111 and rear 112 planar surfaces, and the second portion has non-parallel front 121 and rear 122 planar surfaces. The rear surface of the first portion has a coating 114 for partially reflecting and transmitting light, which may reflect 50% of light. The front surface of the second portion has a coating 123, for reflecting radiation propagating onto the coating from within the beamsplitter, which may reflect 100% of light. The front surface of the first portion and rear surface of the second portion may have anti-reflection coatings 113 & 124. The beamsplitter may be used in a frequency shift monitoring system (200, fig 3) using an etalon (210, fig 3) and tuning arrangement (220, fig 3). |
