Optoelectronic oscillator (OEO) has received growing attentions from researchers in the field of demodulations for optical sensors because its excellent performance combining optics and electronics signal processing. In this article, we present a wideband-tunable OEO angular velocity measurement. The consists two cascaded microwave photonic filters (MPFs), namely, dispersion-induced MPF mainly determining OEO's oscillating frequency two-tap fine selection frequency. With proper control...

A novel photonics-assisted method for tunable microwave frequency comb (MFC) generation based on an actively mode-locked optoelectronic oscillator (AML-OEO) is proposed and experimentally demonstrated in this letter. Two key factors the system, periodic gain modulation widely center frequency, are implemented by externally introduced intensity-modulated optical signal a photonic filter (MPF) phase-shifted fiber Bragg grating (PS-FBG) respectively. Unlike conventional OEO with only one...

A temperature-insensitive magnetic field sensor with high interrogation performance and large measurement range based on an optoelectronic oscillator (OEO) merging a Mach-Zehnder interferometer (MZI) is proposed experimentally demonstrated. In the OEO loop, finite impulse response (FIR)-microwave photonic filter (MPF) infinite response-MPF are cascaded to select oscillating frequency further suppress side mode. The center of FIR-MPF, which composed non-coherent broadband optical source, MZI,...

The polarization effects in tilted fiber Bragg grating (TFBG) refractometers are investigated theoretically. may degrade the sensor performance greatly, and should be considered to achieve high-precision surrounding refractive index (SRI) measurement. possible paths reduce influence of discussed. For large SRI changes, cutoff resonance wavelength can used as sensing parameter a insensitive measurement with linear sensitivity ~500 nm/u.r.i uncertainty ~10 <sup...

The active mode-locking (AML) technique has been widely used in erbium-doped fiber lasers to generate picosecond pulse trains. Here we propose a novel dual-loop optoelectronic oscillator (AML-DL-OEO), which can microwave frequency comb (MFC) signals with adjustable spacings. Based on this scheme, the order of harmonic is dramatically decreased for certain AML driving compared single-loop AML-OEO. Thus, supermode noise caused by be efficiently suppressed. In addition, sidemodes are well...

A switchable, widely wavelength-tunable noise-like pulse (NLP) and Q-switched Er-doped fiber (EDF) laser with a linear cavity structure is proposed experimentally demonstrated in this work. The net-normal-dispersion mode-locked NLP operation based on semiconductor saturable mirror (SESAM) realized 57 nm continuous tuning range from 1528 to 1585 by using tunable filter (TF). When the pump power 500 mW, NLPs produce maximum average output of about 16 mW 3-dB spectral bandwidth 17 at central...

Fundamental and harmonic mode-locking in the dissipative soliton resonance (DSR) regime is experimentally investigated a net-normal-dispersion Er/Yb co-doped fiber laser based on semiconductor saturable mirror (SESAM), where an equivalent narrow-band spectral filter used for triggering multi-pulsing. By monotonically increasing pump power with fixed polarization controller (PC), fundamental operation of DSR pulses can be transformed into (HML) under specific conditions. The main reason...

Mode selection is crucial for a stable single-mode oscillation of an optoelectronic oscillator (OEO). In this article parity-time (PT)-symmetric frequency-tunable OEO proposed and experimentally demonstrated, to realize the precise frequency tuning without using any narrowband filter. The PT-symmetric implemented based on two identical hybrid loops mainly consisting shared dual-parallel Mach-Zehnder modulator (DPMZM) photodetector. PT-symmetry condition can be achieved by enabling...

Recently, optoelectronic oscillators (OEOs) have shown good behavior in microwave signal generation. In this letter, we propose a rational harmonic mode-locking OEO (RHML-OEO) to generate frequency combs (MFCs) with tunable comb intervals. By embedding an extra Mach–Zehnder modulator (MZM) into the cavity, intensity of oscillating mode can be modulated by applied on MZM, and sidebands having fixed phase differences are produced addition mode. A main feature RHML-OEO is that there detuning...

The coexistence of a noise-like pulse (NLP) and dark was experimentally demonstrated in net-anomalous dispersion Er/Yb co-doped fiber (EYDF) laser, for the first time, to our knowledge. cavity mode-locked by nonlinear polarization rotation (NPR) technique. Meanwhile, Sagnac loop with section polarization-maintaining (PMF) used as comb filter enable multiwavelength operation. When PMF length 0.3 m, an asymmetric two-peak spectrum central wavelengths 1565.3 1594.2 nm obtained adjusting...

An anamorphic beam concentrator for linear laser-diode (LD) bar is presented. It consists of a tapered SiO(2)-rod with skewed and curved surface. The principle applicability this device are numerically investigated by ZEMAX experimentally illustrated the specific example LD bar. Results show that relative symmetrical output spot produced at facet rod intensity spatial fluctuations in input compensated distance 20cm from facet.

A fiber with a thin-metallic layer introduced between the central core and cladding is proposed to lift near-degeneracy of modes TE01, TM01, HE21. It can be used obtain pure mode TE01 as both active passive fibers. In case fiber, appropriate rare earth doping profile in presented gain medium laser. The numerical results show that (99.99%) obtained. Gaussian light beams suitable shift distance from center are coupled into fiber. indicate only remains increasing propagation distance.

The mode-selection method based on a single-mode microstructured optical fiber (MOF) in the multicore (MCF) lasers is presented. With an appropriate choice of designed parameters MOF, power coupling coefficient between fundamental mode (FM) MOF and in-phase can be much higher than those FM other supermodes. As result, has highest reflection right-hand side MCF laser cavity, dominates output power. Compared to free-space Talbot cavity method, with as component have effectiveness selection.

It is demonstrated by numerical simulations that the CS2-filled dual-core fiber coupler with appropriate parameters can provide single-mode operation, normal dispersions, low loss and high nonlinearities in 1550-nm 2000-nm wavelength windows, which contribute to a saturable absorber (SA) short length power needed for nonlinearity-induced saturation. The effects of stimulated Raman scattering (SRS) play key role process results indicate SAs be employed mode-locking lasers self-similar (SS) or...