Liang Zhang

Shanghai University | SHU · School of Communication and Information Engineering (SCIE)

A sub-kHz-linewidth broadband-swept fiber laser using Rayleigh scattering-based Brillouin random lasing oscillation is proposed and experimentally demonstrated. Benefiting from Brillouin-involved acoustic damping and arbitrary-wavelength distributed Rayleigh feedback, leveraging instantaneously tuning Brillouin gain spectrum induced by a frequency-...

In this paper, we propose and demonstrate an all-optical control of RSB transition in a multi-wavelength Brillouin random fiber laser (MWBRFL). Multi-order Stokes light components can be subsequently generated by increasing the power of the Erbium-doped fiber amplifier (EDFA) inside the MWBRFL, providing additional disorder as well as multiple Stok...

Perfluorinated acrylate polymer materials exhibit low absorption loss at 1310 and 1550 nm, but molecular oxygen inhibits their photocuring. We propose a novel, to our knowledge, UV photolithography method incorporating a pre-exposure process for fabricating low-loss perfluorinated acrylate polymer waveguides. During the pre-exposure process, a part...

A low-noise Brillouin random fiber laser (BRFL) based on dynamic fiber grating (DFG)-assisted self-injection locking (SIL) as a laser carrier for coherent communication is proposed and experimentally demonstrated. The utilization of the DFG-based SIL basically guarantees an innovative purification of ultra-narrow-linewidth laser radiation after the...

Current or magnetic field sensing is usually achieved by exploiting the Faraday effect of an optical material combined with an interferometric probe that provides the sensitivity. Being interferometric in nature, such sensors are typically sensitive to several other environmental parameters such as vibrations and mechanical disturbances, which, how...

A distributed optical fiber magnetic field sensor based on a polarization-sensitive optical frequency domain reflectometer (POFDR) is proposed. It extracts the accumulated Faraday rotation by combining the Stokes vectors and the backward Mueller matrices from the measured states of polarization (SOPs) and obtains the magnetic field component. This...

A design of a heterogeneous integrated optical fiber with side nickel core (SNCF) has been proposed and demonstrated for distributed fiber-optic magnetic field sensing. Experimental results show that magnetic properties of nickel can be preserved well after the high temperature drawing process. The functionality of the SNCF has been well verified,...

A heterogeneously integrated fiber-optic magnetic field sensor is proposed and demonstrated in this work. The sensing fiber is thermally drawn and consists of a nickel side-core, a silica center core and a silica cladding. When exposed to the external vertical magnetic field, the Lorentz force will be generated in the electric current applied nicke...

We numerically and experimentally demonstrated a high-sensitivity and high-accuracy temperature sensor based on guided acoustic radial modes of forward stimulated Brillouin scattering (FSBS)-based optomechanics in thin-diameter fibers (TDF). The dependence of the FSBS-involved electrostrictive force on the fiber diameter is systematically investiga...

In this work, a cylindrical vector beams-based magnetic field sensor was proposed and demonstrated by using an yttrium iron garnet (YIG) crystal as the magneto-optical medium. The first-order cylindrical vector beam transmitted through a linear polarizer behind the YIG becomes a two-petal patterned light. When its polarization was rotated by the Fa...

Replica symmetry breaking (RSB), as a featured phase transition between paramagnetic and spin glass state in magnetic systems, has been predicted and validated among random laser-based complex systems, which involves numerous random modes interplayed via gain competition and exhibits disorder-induced frustration for glass behavior. However, the dyn...

Orbital angular momentum (OAM) mode division multiplexing (MDM) amplification in a seven-ring-core erbium-doped fiber (7-RC-EDF) has been experimentally demonstrated, in which the 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> -4 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xli...

An all-fiber fiber coupler was demonstrated for pumping orbital angular momentum (OAM) modes amplification, which was fabricated by side-polishing and bonding a ring-core erbium-doped fiber (RC-EDF) and a pre-tapered side-polished single-mode fiber (SMF). With the selected phase-matching condition at 976 nm, the pumping laser was coupled into the R...

We demonstrate a narrow-linewidth high-order-mode (HOM) Brillouin random fiber laser (BRFL) based on a long-period fiber grating (LPFG) and distributed Rayleigh random feedback in a half-open linear cavity. The single-mode operation of the laser radiation with sub-kilohertz linewidth is achieved thanks to distributed Brillouin amplification and Ray...

The intra-mode forward stimulated Brillouin scattering activated by an interplay between high-order vector optical modes and transverse acoustic waves in few-mode fibers is theoretically and experimentally demonstrated.

We theoretically investigate the forward stimulated Brillouin scattering (FSBS) of microfibers with elliptical transverse profile, revealing distinctive FSBS frequency dependence on the fiber geometry.

A high-order-mode Brillouin Random fiber laser with high purity and broadband tunability based on a long-period fiber grating and distributed Rayleigh scattering in optical fibers was demonstrated.

Temperature fiber sensing based on high-order optical modes-activated intra-mode forward stimulated Brillouin scattering in few-mode fibers has been theoretically and experimentally demonstrated.

We demonstrated a high-sensitivity temperature sensor based on guided acoustic radial modes of forward stimulated Brillouin scattering in thin-core fibers, allowing the enhanced sensitivity linearly dependent on the order of activated radial modes.

Cascaded Brillouin random fiber lasers (BRFLs) with laser linewidth compression were theoretically and experimentally demonstrated. Thanks to photon-phonon coupled interplay as well as randomly distributed feedback along silica fibers, the coherent time of cascading BRFL radiation is significantly prolonged whilst the phase noise is further suppres...

An all-silica Fabry-Perot interferometer (FPI) based on a microbubble for high-pressure and high-temperature measurements is proposed and demonstrated. The microbubble-based air cavity is fabricated using a hollow silica tube and a single-mode optical fiber for pressure sensing. The suitable thickness between the two end faces of the microbubble en...

We proposed and demonstrated an unprecedented high-efficiency Brillouin random fiber laser (BRFL) by fiber length optimization in a half-open linear cavity. In terms of the trade-off between Brillouin gain saturation and weak distributed Rayleigh feedback strength, optimal laser efficiency associated to proper fiber length in a BRFL was theoretical...

We demonstrated that a ring-core erbium-doped fiber amplifier (RC-EDFA) can support orbital angular momentum (OAM) modes with topological charges (|l| = 1~3). The dependence of the characteristics on the length of the RC-EDF was investigated experimentally, including an investigation of gain and 3 dB gain bandwidth over the whole C band (i.e., 1530...

A Gaussian-like reversed ridge optical waveguide based on the perfluorinated acrylate polymer is fabricated by an improved UV photolithography with the pre-exposure process. A partially cured thin layer is formed on the lower cladding during the pre-exposure process, which will avoid the effect of the oxygen inhibition in the following UV photolith...

A broadband fiber-optic acoustic sensing system is proposed and demonstrated, which is configured by a fiber Bragg grating (FBG) and an erbium-doped fiber (EDF) ring laser. As the acoustic waves can shift the FBG reflective spectrum, the wavelength of the laser output shifts accordingly and this shift is subsequently converted into a corresponding...

In this study, a sapphire-derived fiber (SDF)-based Fabry-Pérot interferometer (FPI) is proposed and experimentally demonstrated as a high-temperature sensor using the arc discharge crystallization process, forming a region with disordered mullite grains. This shows that the disordered mullite grains are related to the gradual temperature distribut...

A flexible first-order OAM modes generation in ring-core fibers (RCFs) based on a mechanically-induced long-period fiber grating (MLPFG) is proposed. By directly fusion splicing a standard single-mode fiber (SMF) and RCFs, the anti-resonant reflection guidance mechanism (ARRGM) is introduced in the RCF, leading to the guided-core modes, so-called a...

We have proposed and designed a fiber-optic magnetic field sensors based on magnetostriction, of which the magnetostrictive induced strain of magnetostrictive rod attached to an optical fiber can be measured by optical frequency-domain reflectometry (OFDR). By analyzing the stress transfer process at the interface between the magnetostrictive rod a...

We demonstrated a stabilized Brillouin random fiber laser based on external injection of the 2 nd order Stokes for the first time, benefiting a dynamic gain-loss balance for relative intensity noise suppression under optimized injection power.

We experimentally demonstrated Brillouin-induced fast light based on Rayleigh scattering-assisted half-open random lasing oscillation along kilometers optical fibers, providing enhanced all-optical manipulation of light group velocity.

A frequency-stabilized Brillouin random fiber laser (BRFL) realized by a self-inscribed transient population grating (TPG) is proposed and demonstrated for the first time, to the best of our knowledge. The TPG is formed via the redistribution of the population in erbium-doped fibers (EDFs) by bidirectionally injected phonon-controlled random laser...

This paper comprehensively investigated noise characteristics of superluminal propagation based on low-noise single-frequency Brillouin lasing oscillation with the aid of a population inversion dynamic grating. Thanks to high-degree polarization alignment between the Brillouin pump and the lased Stokes lightwaves in polarization maintaining fibers,...

We experimentally demonstrated Brillouin-induced fast light based on random lasing oscillation with random feedback of distributed Rayleigh scattering in optical fibers.

We experimentally investigate two schemes of Brillouin random fiber laser (RFL) by using high-order-mode (HOM) pump in a few-mode fiber (FMF). The core-mode conversion between LP01 and LP11 modes is obtained in the FMF by cascading long period fiber gratings (LPFG) working at the same wavelength region. Different transversal modes of stimulated Bri...

We have proposed and experimentally demonstrated a sapphire-derived fiber (SDF) and silica capillary-based compound Fabry-Pérot interferometer (FPI) for high-pressure and high-temperature sensing. The SDF owns high alumina dopant concentration core, which can generate a mullite crystallization region during an arc discharge process. The crystalliza...

Based on the unique polarization characteristic of the cylindrical vector beam, a new-type vector magnetic field sensing technique is proposed. As the cylindrical vector beam passes through a magnetic fluid film, a polarization analyzer is used to detect the polarization state change of the output light after passing through a slit. Based on the bi...

An all-silica Fabry-Prot interferometer (FPI) is demonstrated for high-temperature pressure monitoring. The pressure sensor is fabricated with single mode fiber and silica capillary by CO2 laser. Owing to slight mismatch of thermal expansion coefficient in all-silica structure, it can work stably under 600C atmosphere. The influence of the temperat...

This paper demonstrates an underwater localization system based on an improved phase-sensitive optical time domain reflectometry (φ-OTDR). To localize the underwater acoustic source, 3D-printed materials with relatively high Poisson's ratio and low elastic modulus are wrapped by single-mode optical fibers to serve as an L-shaped planar sensing arra...

Vortex beams have attracted much attention in recent years due to unique features of the phase or polarization singularity in the center part of beams. Various applications have been explored by the vortex beams including optical communication, optical tweezer, etc . Especially, the vortex beams for optical sensing applications have emerged. Comp...

We experimentally demonstrated that the transversal vortex modes of an all-fiber erbium-doped Brillouin laser can be dynamically switched by using the high-order mode (HOM) of Brillouin pump (BP), which is used to achieve the oscillation of HOM inside the ring cavity. Core-mode conversion in a few-mode fiber (FMF) between the fundamental mode and H...

A Mach–Zehnder interferometer (MZI) sensor based on a four-core sapphire-derived fiber (FSDF) for bending sensing is proposed and demonstrated. The MZI is formed by splicing a coupled FSDF between two single-mode fibers, delivering supermode interference among four LP01-like supermodes (LP01s modes) and eight LP11-like supermodes (LP11s modes). Ben...

We demonstrated spectral purification of random lasing emission in a Brillouin random fiber laser by employing a self-tracking dynamic fiber grating with unpumped Erbium doped fibers.

We experimentally achieved stabilized Brillouin-induced fast light and superluminal propagation in kilometer-long optical fibers by introducing linearly polarized single-longitudinal-mode Stokes lasing resonance.

This paper reported the experimental evidence of replica symmetry breaking in a random fiber laser incorporating nonlinear Brillouin gain and distributed Rayleigh random feedback.

We demonstrated a high-efficiency random fiber laser based on hybrid gain mechanism of Brillouin and Erbium-doped fiber amplification as well as distributed random feedback from a weak FBG array.

We demonstrated a highly sensitive underwater acoustic wave detection by incorporating 3D-printed sensing elements in phase-sensitive Optical Time Domain Reflectometry (φ-OTDR), giving rise to one-order of magnitude enhanced signal-to-noise ratio (SNR).

A self-inscribed dynamic fiber grating as an auto-tracking mode selective element is embedded into a Brillouin random fiber laser, yielding a frequency stabilized Stokes random lasing radiation with highly suppressed modes hoping.