Ultrafast time-stretch imaging at 932 nm through a new highly-dispersive fiber

Abstract

Abstract:Optical glass fiber has played a key role in the development of modern optical communication and attracted the biotechnology researcher's great attention because of its properties, such as the wide bandwidth, low attenuation and superior flexibility. For ultrafast optical imaging, particularly, it has been utilized to perform MHz time-stretch imaging with diffraction-limited resolutions, which is also known as serial time-encoded amplified microscopy (STEAM). Unfortunately, time-stretch imaging with dispersive fibers has so far mostly been demonstrated at the optical communication window of 1.5 μm due to lack of efficient dispersive optical fibers operating at the shorter wavelengths, particularly at the biofavorable window, i.e., <1.0 μm. Through fiber-optic engineering, here we demonstrate a 7.6-MHz dual-color time-stretch optical imaging at bio-favorable wavelengths of 932 nm and 466 nm. The sensitivity at such a high speed is experimentally identified in a slow data-streaming manner. To the best of our knowledge, this is the first time that all-optical time-stretch imaging at ultrahigh speed, high sensitivity and high chirping rate (>1 ns/nm) has been demonstrated at a bio-favorable wavelength window through fiber-optic engineering.

Principle and Recent Development in Photonic Time-Stretch Imaging

“…The recent development of PTS imaging systems are mainly in four categories: first, PTS imaging systems combined with shorter wavelength bands for better imaging resolutions and rich applications [68][69][70][71][72][73]; second, PTS imaging systems with faster speed [21,22,[26][27][28][29]57,58,74,79]; third, PTS imaging systems combined with data compression [11][12][13][14][15][16][17][18][75][76][77][78]; and the last, PTS imaging systems combined with deep learning for target classification [23][24][25]32,66].…”

“…Among the improvement of current imaging systems, improving temporal resolution attracts a large amount of attention and obtained fruitful achievement. The most sparking technique for improving temporal resolution for imaging systems is PTS [66][67][68][69][70][71][72][73][74]-a technique that encodes the spatial profile of sample imaging information into the temporal profile data for ultrafast imaging using the dispersive medium in both spatial and temporal domains based on the dispersive properties of broadband light. It was proposed and demonstrated by Goda et al in 2009 for the first time [59].…”

All-passive pixel super-resolution of time-stretch imaging

“…S1(e) ]. It takes advantage of the non-uniform illumination background of the line-scan (mapped from the laser spectrum) as the reference, thanks to the superior shot-to-shot spectral stability offered by the broadband mode-locked laser 5 24 25 26 . Based on the balance between the spectral broadening and gain-narrowing in the all-normal dispersion cavity this pulsed laser, which is home-built based on off-the-shelf fiber components, also provide negligible timing jitter ( Supplementary Fig.…”

Nd-Doped Polarization Maintaining All-Fiber Laser With Dissipative Soliton Resonance Mode-Locking at 905 nm

“…Finally, neodymium doped (Nd-doped) double-clad fiber with a W-type core refractive index profile was implemented as a gain medium. It creates an effective cutoff wavelength of the LP01 mode at longer wavelengths that led to this mode suffer from high losses distributed along the fiber, resulting in sufficient decrease of the gain at 1060 nm [28], [30], [33]. The works mentioned above have successfully demonstrated ultrafast operation based on the nonlinear polarization evolution, nonlinear amplifying loop mirror (NALM) or SESAM.…”