The optical vector analyzer is a device used to measure the magnitude, phase responses, and other parameters of optical devices. There have been increasingly higher demands placed on optical vector analyzers during the development of optical technologies, which are satisfied by the creation of new devices and their operating principles. For further development in this area, it is necessary to generalize the experience gained during the development of optical vector analyzers. Thus, in this report, we provide an overview of all the basic types of approaches used for the realization of optical vector analyzers, including the advanced ones with the best performances. The principles of their working, as well as their associated advantages, disadvantages, and existing solutions to the identified problems, are examined in detail. The presented approaches could be of value and interest to those working in the field of laser dynamics and optical devices, as we propose one use of the optical vector analyzer as being the characterization of Fano resonance structures.

We report on the numerical simulations and experimental validation of a microwave planar sensor based on two coupled rings operating in the 4–6 GHz range. The fabricated sensor is used to characterize the dielectric permittivity of vegetable oils. We optimized the geometrical parameters in order to improve the overlap between the oil samples under study and the electric field. The experimental results showed an excellent match with the simulation results. The fabricated sensor allowed to retrieve the oil permittivity with a sensitivity of about 35 MHz per permittivity unit in the frequency range of interest. This paves the way to the realization of compact and sensitive sensors for a wide plethora of fields ranging from industry and food to chemistry and biology.

This article describes the design principles of optoelectronic system (OES) for instantaneous frequency measurement (IFM) of microwave signals based on the use of amplitude-phase modulation conversion of single optical carrier into symmetrical dual-frequency signal for additional frequency separation, its modulation by unknown frequency and subsequent “frequency-amplitude” measurement conversion in Fiber Bragg Grating (FBG) with Gaussian reflection profile. Such approach allows increasing of measurement resolution at low frequencies.

This article describes the design principles of instantaneous frequency measurement system of microwave signals based on the use of amplitude-phase modulation conversion of single optical carrier into symmetrical dual-frequency ones for additional frequency separation according its wavelength range, and same its modulation by unknown frequency and subsequent “frequency-amplitude” measurement conversion in fiber Bragg grating with Gaussian reflection profile. Distinction and measurement of the instantaneous frequencies made depending on the amplitudes, modulation indexes and form of the signals on the difference frequency envelope of unknown frequency components, received at the photodetector in two separated ranges 0,25-12,5 GHz and 12,5-25 GHz. Such approach increases the SNR and allows measuring of several unknown frequencies simultaneously vs classical IM-DD approach in FBG based systems of given type. From another side this method realization have to use expensive wideband photoreceiver. The main purpose of article is to show how to decrease bandwidth of system photoreceiver in two times.

Photonic-assisted receivers for instantaneous microwave frequency measurement are devices used to measure the instantaneous frequency and amplitude of one or more microwave signals in the optical range, typically used in radar systems. Increasingly higher demands are placed on frequency range, accuracy and resolution during the development of instantaneous microwave frequency measurement applications, and these demands can be satisfied by the creation of new devices and operating principles. To permit further development in this area, it is necessary to generalize the experience gained during the development of devices based on frequency and amplitude discriminators of resonance type, including advanced ones with the best performances. Thus, in this report, we provide an overview of all the basic types of approaches used for the realization of photonic-assisted receivers based on fiber Bragg gratings, integrated Fano and optical ring resonators, Brillouin gain spectrum, and so on. The principles of their operation, as well as their associated advantages, disadvantages, and existing solutions to identified problems, are examined in detail. The presented approaches could be of value and interest to those working in the field of microwave photonics and radar systems, as we propose an original method for choosing photonic-assisted receivers appropriate for the characterization of multiple frequency measurements.