A Unified Framework for Photonic Time‐Stretch Systems

Abstract

Photonic time stretch is the key enabling technology for a wide variety of instruments with unparalleled single-shot data acquisition performance at high throughput and continuous operation. These systems have established landmark performance in spectroscopy and imaging including flow-through microscopy, velocimetry, lidar, and other measurements. The evolution of the original time-stretch technique into such diverse instruments and applications over the last 25 years has created the need for a unified theoretical framework. This paper represents the first step toward a universal mathematical model for time-stretch instruments. It shows that the "stretch factor"-the fundamental performance metric-is governed by a single canonical equation in a wide range of seemingly diverse time-stretch instruments. The paper also provides new insight into the operation of time-stretch imaging and light scattering systems. The stretch factor is derived for time-stretch systems that operate in temporal, spatial, angular, and Doppler domains. The analysis and mathematical tools provided here can facilitate understanding and analysis of such systems and help future developments in this field.

Single-Photon Level Dispersive Fourier Transform: Ultrasensitive Characterization of Noise-Driven Nonlinear Dynamics

“…This hints toward the potential of further DFT temporal stretching of the optical spectrum, which was here limited by the laser repetition rate and available dispersive fiber module. However, we expect that advanced DFT processing − such as pulse picking and recirculating fiber loop should be capable of yielding extreme DFT broadening, thus pushing forward the limits of achievable DFT spectral resolution toward the picometer range while, conversely, alleviating the need for expensive low-jitter SPD detection schemes for setups with demanding sensitivity needs but less stringent resolution requirements.…”

“…Over the years, numerous advances in characterization techniques occurred and proved essential in the measurement of ultrashort pulses, associated with broadband spectral signals in the frequency domain. Techniques inherently based on dispersive time-stretch, − such as dispersive Fourier transform (DFT) , and time-lens (TL) , systems, proved successful for the characterization of incoherent processes requiring the measurement of ultrafast and non-repetitive events. Specifically, DFT transforms a broadband optical signal into a time-stretched waveform replica of the spectrum. , The analogous spectral waveform can thus be readily captured with a single-shot measurement of the temporal intensity profile. ,− DFT thus allows for the rapid acquisition and the subsequent analysis of large spectral data sets as required for the study of statistical outliers, , fast dynamical evolution, , or the implementation of machine learning in photonics. , …”

“…Specifically, DFT transforms a broadband optical signal into a time-stretched waveform replica of the spectrum. 4,5 The analogous spectral waveform can thus be readily captured with a single-shot measurement of the temporal intensity profile. 4,10−12 DFT thus allows for the rapid acquisition and the subsequent analysis of large spectral data sets as required for the study of statistical outliers, 13,14 fast dynamical evolution, 15,16 or the implementation of machine learning in photonics.…”

Physics-AI symbiosis

“…The current release of PhyCV has two algorithms for computationally efficient edge and texture extraction: Phase-stretch transform (PST) [34] and Phase-Stretch Adaptive Gradient-Field Extractor (PAGE) [35,36]. They are originated from photonic time stretch [37], a hardware technique for ultrafast and single-shot data acquisition. The algorithms emulate the propagation of light through a 2D physical medium with natural and artificial diffractive properties followed by coherent, i.e.…”

Fast and slow optical rogue waves in the fiber laser

“…Fiber lasers are an ideal platform and perfect candidates for discovering and investigating the formation of single-shot ultrafast rare events such as optical RWs [2][3][4][5][6][7][8]. It provides an opportunity to obtain a vast amount of data under laboratorycontrolled conditions in a relatively short time.…”