| 摘要 |
FIELD: physics. ^ SUBSTANCE: device has a low-coherent light source optically connected to the first input/output of a single-mode fibre-optic splitter, the common input/output of which is optically connected to a first plate, and its second input/output is optically connected through a fibre-optic depolariser to the first input/output of single-mode fibre-optic splitter. The second, third and fourth inputs/outputs of the splitter are respectively optically connected to a second plate placed in a temperature-controlled cabinet, second and first photoconverters which are connected by their outputs to inputs of a signal ratio metre. The thickness D1 of the first plate and the thickness D2 of the second plate satisfy the relationship: 2n(T)ù(D1-D2)<Lk, where n(T) is the temperature dependence of the refraction index of the material of the plate and Lk is the longitudinal coherence length of the light source. ^ EFFECT: simple design, reduced weight and size and high measurement accuracy. ^ 2 cl, 1 dwg |
