A microwave channelizer and spectroscope based on an integrated optical Bragg-grating Fabry-Perot and integrated hybrid Fresnel lens system

Abstract

A compact means to separate microwave and millimeter-wave optical signals by RF frequency in real time is demonstrated. The approach is to employ an integrated optical Bragg grating Fabry-Perot (BGFP) device to spatially separate optically modulated microwave signals with high resolution. The compactness is achieved through the use of an integrated optical hybrid diffractive lens beam expander to provide the required optical wavefront to the BGFP. A proof-of-principle measurement was performed from 1 to 23 GHz with peak finesse of 27. The theoretical analysis, fabrication procedure, experimental results, limitations, and improvements are described.

Photonics-enabled sub-Nyquist radio frequency sensing based on temporal channelization and compressive sensing

“…Note that the effective frequency measurement resolution is determined by the temporal aperture of the stretched optical pulse and estimated as 196 MHz, which is more than 100 times higher than that in conventional channelizer-based RF spectrum sensing systems where the resolution is determined by the channel spacing [4][5][6]. In addition, as the SLM needs no refreshing to achieve random mixing, the system proposed features single-shot measurement with an update rate identical to the repetition rate of the pulse train, which is 50 MHz in this work.…”

“…Photonically assisted techniques for RF spectrum measurement have shown superior performance over their electronic counterpart, due to the distinct advantages such as large bandwidth, low loss, low cost, and immunity to electromagnetic interference. Many solutions have been proposed for photonic RF spectrum sensing in the past a few years, including those based on microwave/optical power monitoring [2,3], channelization [4][5][6], and time-delay based phase discrimination [7,8].…”

Analysis of a Polynomial System Arising in the Design of an Optical Lattice Filter Useful in Channelization

“…Ingredients such as frequency down-conversion may be realized using optical heterodyne detection, [16]. Many researchers have proposed optical channelizers using free space diffraction grating, Bragggrating Fabry-Perot cavity, ring resonators, [15,[17][18][19][20][21]. These are all passive devices and thus don't possess adequate tunability.…”

Performance of Instantaneous Microwave Analysis by Parametric Channelized Receiver Through Time Domain Monitoring

“…Channelized receiver approaches based on free-space diffraction grating [2], Fresnel lens system [3], or array of phase-shifted fiber Bragg gratings [4] have been proposed and demonstrated. A different class of photonic channelized receiver, based on the copying of the original RF signal onto an array of uniformly spaced optical carriers followed by filtering through a periodic filter, has been more recently studied [5]- [9].…”