Optical device measuring method and device based on double sideband modulation

Abstract

The invention discloses an optical device measuring method and device based on double sideband modulation, which belongs to the technical fields of optical device measuring and microwave photonics. An optical double sideband modulation method is used to modulate a radio frequency signal to a first optical carrier signal, so as to generate a double sideband modulation signal. The double sideband modulation signal passes through an optical device to be measured to carry out beam combining with a second optical carrier signal. Frequency difference is between the second optical carrier signal and the first optical carrier signal. A photoelectric detector is used to carry out beat frequency on the signals after beam combining. The amplitude information of a +1 order sideband signal and a -1 order sideband signal in the beat frequency signals is extracted. The frequency of the radio frequency signal is scanned, so as to acquire the broadband amplitude frequency response of the optical device to be measured. The invention further discloses an optical device measuring device based on double sideband modulation. According to the invention, the system complexity and the cost are reduced; the measuring range and the measuring efficiency are greatly improved; and more importantly, a new direction is opened up for an optical device measuring technology.

Description

technical field [0001] The invention relates to an optical device measurement method, in particular to an optical device measurement method and a measurement device based on double sideband modulation, and belongs to the technical fields of optical device measurement and microwave photonics. Background technique [0002] In recent years, with the rapid development of laser technology, photonic systems have been widely used, such as ultra-high-precision optical fiber sensing, long-distance optical fiber communication, etc. However, the development of optical measurement technology has stagnated, which not only makes it difficult to develop and manufacture high-precision optical devices, but also makes it impossible for existing optical devices to maximize their effectiveness in optical systems. For example: the minimum bandwidth of Fiber Bragg Grating (FBG) is as low as 9MHz, while the measurement accuracy of existing optical measurement technology is still hundreds of MHz (c...

AI Technical Summary

Problems solved by technology

[0004] However, the measurement method of optical devices based on SSB modulation also has serious deficiencies

First of all, the generation of optical SSB will make the system very complicated. The current SSB generation methods are roughly divided into filtering method and 90° phase shift method. The former requires the use of filters, which increases the complexity and instability of the system, and The extinction ratio is limited; the latter requires a 90° phase shift of the microwave signal loaded to the dual-drive optoelectronic modulator, requiring the use of a broadband 90° bridge and a dual-drive optoelectronic modulator, the system is complex and inconvenient to adjust

Secondly, the SSB frequency sweep method can only obtain a set of measurement signals in one measurement, and the measurement efficiency is low.

Finally, the SSB sweep method is severely limited by the instrumentation, e.g. the SSB sweep range cannot be larger than the photodetector (PD) bandwidth

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