Interferometer

Abstract

The invention relates to the optical communication field, in particular relating to a demodulator and a detector used for optical phase signal detection. An interferometer provided by the invention comprises an optical beam splitter, a right-angle reflecting mirror and a piece of plate glass, wherein the optical beam splitter is used for splitting an incident optical beam into two parallel beams to output and consists of a rhombus prism member and a right-angle prism member, and the two members are bonded to each other and form a spectro-film with the ratio of transmission to reflection being 50:50; the right-angle reflecting mirror is used for retracing the above two parallel optical beams to the optical beam splitter in a parallel manner and generating interference after reflecting by two right-angled reflectors thereof; and the plate glass is arranged between the optical beam splitter and the right-angled reflectors, and the optical beam splitter and the right-angled reflectors are connected into a whole by two parallel side surfaces at the two sides of the plate glass. In the retracing process of the two sub optical beams split by the optical beam splitter, an optical path difference (OPD) which is calculated by multiplying duple thicknesses of the rhombus prism by the material refractive index of the rhombus prism exists, which is unrelated to the distances between the right-angled reflectors and the optical beam splitter.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to a demodulator and a detector for optical phase signal detection. Background technique [0002] Phase-shift keying (PSK) modulation technology and coherent detection technology can effectively reduce the influence of dispersion and PMD on signals in ultra-high-speed optical transmission networks, but none of the existing optical detectors can directly respond to the phase information of light. The loaded phase signal must be converted into an intensity signal and then demodulated by means of light intensity detection. In order to convert the phase signal into an intensity signal, an existing basic principle is to interfere the beams of the same frequency, because the light intensity I of the interference wave is different from the phase difference of the two beams participating in the interference available formula Indicates that I 1 , I 2 is the peak light intensity of ...

AI Technical Summary

Problems solved by technology

However, since the optical elements passed by the separated beams are not the same, the processing size error between the elements will make it difficult to maintain the same design requirements for the optical path distance, so it is forced to increase the processing accuracy requirements of the optical elements

For example, glass flat sheet 14 and glass flat sheet 22 in the figure hope to have the same thickness (or a very small thickness difference) according to the design requirements. To achieve this requirement of two different flat sheets, the glass flat sheet must be The thickness tolerance is set to the corresponding requirements, which also increases the difficulty of actual production

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