Measurement of optical magnitude response based on double-sideband modulation

Abstract

A novel approach to perform high-resolution optical magnitude response measurements, using optical double-sideband (ODSB) modulation, is proposed and experimentally demonstrated. As compared with a conventional optical single-sideband modulation-based optical magnitude response measurement, the proposed method based on ODSB modulation features not only simple configuration and doubled measurement range, but also immunity to modulation nonlinearity. A proof-of-concept experiment is carried out. The magnitude response of a fiber Bragg grating (FBG), in the range of 40 GHz, was measured with a resolution of 10 MHz, by using a 20 GHz microwave signal source.

Ultrahigh-Resolution Optical Vector Analyzers

“…To simultaneously solve the problems described above, OVAs based on optical dual-sideband (ODSB) modulation were created [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. They have the following advantages: A doubled measurement frequency range up to 80 GHz with an element base based on lithium niobate (LiNbO 3 ), and an ultrahigh resolution of about 667 kHz, which depends on the quantity of control points of measurements of the electrical vector network analyzer, and which can be increased.…”

“…The carrier shift problem was solved in [24] by separating the carrier and scanning sidebands along parallel channels (Figure 8). ESA-electrical spectrum analyzer; red lines-optical signal; blue lines-electrical signal; dotted line-data path; ω 0 -the frequency of the optical carrier; ω m -the modulation frequency; ∆ω-a fixed frequency shift (adapted from [24]).…”

“…The approach described in [24] was improved in [26], the main advantage of which is a self-calibration of measurement results. The difference between this scheme and the previous one is that in the measuring channel the signal after the modulator was divided into two parts.…”

“…A fundamentally new approach based on this method was proposed in [28]. The schematic diagram of this device is similar to the schematic diagram in [24], however, a different measurement principle was implemented. It was proposed here to analyze not only the beats of the shifted carrier and the first-order sidebands, but also the beats between the carrier and second-order sidebands.…”

Optical vector analysis based on asymmetrical optical double-sideband modulation using a dual-drive dual-parallel Mach-Zehnder modulator

“…Recently, an OVA based on optical double-sideband (ODSB) modulation is proposed [17,18], which characterizes the optical devices using both of the two first-order sidebands without frequency aliasing by shifting the frequency of the optical carrier. Compared with the OSSB-based OVA, the ODSB-based OVA has a doubled measurement range, and better nonlinearity immunity which leads to a higher accuracy and a larger dynamic range.…”