Multimode fibers (MMFs) have the potential to carry complex images for endoscopy and related applications, but decoding speckle patterns produced by mode-mixing modal dispersion in MMFs is a serious challenge. Several groups recently shown that convolutional neural networks (CNNs) can be trained perform high-fidelity MMF image reconstruction. We find considerably simpler network architecture, single hidden layer dense network, performs at least as well previously-used CNNs terms of...

Cyclic olefin polymer (COP) is newly used as the inner dielectric of infrared, hollow glass waveguides because its low extinction coefficient in mid-infrared region. A liquid-flow coating and dry-cure process are employed to form COP layer on inside a silver-coated tube. In process, cyclohexane chosen solvent smooth uniform layer. It shown that COP-coated silver show loss properties for CO(2), CO, Er:YAG laser light when thickness properly chosen.

We propose a simple method to mitigate the cross phase modulation (XPM) effect in wavelength division multiplexing (WDM) systems, which combines split nonlinearity compensation (NLC) and receiver-side recovery algorithm. In proposed method, NLC can suppress conversion from nonlinear noise (NLPN) Gaussian-like interference (NLIN), together with algorithm, compensate for NLPN, impact of XPM on signal is finally mitigated. This demonstrated by transmission simulation 11 WDM channels 32 Gbaud 16...

Hollow fibers for CO(2) laser light have been fabricated with a cyclic olefin polymer as the inner dielectric. A film of was coated inside glass capillary tubing by simple liquid-flowing process. polymer-coated fiber 700-microm bore showed loss 0.06 dB/m because has low absorption at 10.6-microm wavelength.

The variation in properties of a fluorocarbon polymer (FCP) film during drying-curing process is investigated for fabricating FCP-coated silver (FCP/Ag) hollow glass waveguides. A dynamic liquid-phase coating procedure used. Through the analyses loss spectra waveguides made various conditions, relationship between thickness FCP and velocity obtained. optimum fabrication condition also established producing FCP/Ag mid-IR.

Refractive indices and extinction coefficients of several polymers have been measured for the wide infrared wavelength region. The used as coating materials also found useful low-loss hollow waveguides transmission Er:YAG, CO, CO(2) laser light, respectively.

In this paper, we present an accurate theoretical description of the birefringence characteristics in a Nd : YAG rod by taking thermal lens effect into account. Considering that is strongly dependent on distance away from centre birefringent rod, convergent features incident probe beam were first evaluated for side-pumped laser rod. A segmental accumulation method was then employed to calculate total phase shift between radial and tangential components polarization converged beam. The...

This paper proposes a novel optical time domain reflectometry (OTDR) method based on the digital linear frequency modulation (LFM) pulse, which can achieve tradeoff between maximum measurable distance and spatial resolution. Direct detection are adopted at transmitting receiving ends, respectively, is simple in construction does not require additional optics. The short-time fractional Fourier transform (STFrFT) introduced for signal processing noise filtering. theoretical analysis of working...

We propose and experimentally demonstrate a novel cost-effective distributed in-band optical signal-to-noise ratio (OSNR) monitoring method using widely tunable bandpass filter power measurements, which employs the Gaussian process regression is proved to be insensitive fiber nonlinearity, chromatic dispersion, amplifier type. This verified in 9-channel 10 Gbaud NRZ-QPSK coherent transmission system with 50-GHz channel intervals. When there are no add-drop filters or wavelength selective...

We presented a Nd:YAG master oscillator power amplifier (MOPA) with the compact LD double-end pumped configuration. To acquire homogenous absorption distribution, composite short rod has been employed as amplification medium and side was well polished to cause total internal reflection (TIR) at wall of rod. Because axes pump LDs seed laser occupy same position, it is relatively easy obtain both satisfied mode-matching efficiency high by using two stacked-LD modules. A laser, input energy 15...

An 8 × 16 wavelength selective switch (WSS) with full contentionless switching is proposed and experimentally demonstrated. Utilizing two chips of liquid crystal on silicon, the optical wavelengths can be switched, attenuated, or blocked among input ports output ports. The maximum insertion loss less than 14 dB; bandwidth tuning range from 50 to 5000 GHz. attenuation 0 15 dB, blocking value greater 27 dB. Compared previous reports, WSS in this letter a truly device highest number

A systematic method has been proposed to evaluate the complex refractive indices and thicknesses of dispersive polymer thin films in both visible infrared regions. The curve-fitting applied measurement film near-infrared accuracy evaluated thickness is order +/-0.5%. presented useful for characterizing optical properties polymers whose are near those substrates.

Polyimide-coated silver hollow glass waveguides with small losses have been fabricated for transmission of Er:YAG laser light. The total loss is around 0.7 dB the straight waveguide an inner diameter 700 micrometers and length 2.3 m including a coupling from laser. Even when bent to 180 degrees bending radius 18 cm, 1 input energy 500 mJ.

A large number of solutions have been proposed to support mobility in IP networks including original Mobile IP, its derivatives and several newly protocols. However, these often show drawbacks terms triangle routing, handoff inefficiency, heavy signaling overhead, etc. when handling diversified scenarios. In this paper, we argue that problems can be addressed by an adaptive solution based on software-defined (SDN). We discuss why SDN helps solve the current protocols give our design...

We propose and experimentally demonstrate modulation format-independent optical performance monitoring (OPM) based on a multi-task artificial neural network (MT-ANN). Optical power measurements at series of center wavelengths adjusted using widely tunable bandpass filter (OBPF) are used as the input features for MT-ANN to simultaneously realize high-precision signal-to-noise ratio (OSNR) launch baud rate identification (BRI). This technique is insensitive chromatic dispersion (CD)...

In this study, we derive a theoretical and experimental expression for evaluating the thermally induced birefringence (TIB) in Nd : YAG laser system with double rods tandem. The analytical solution determines optimum oscillator geometry corresponding to minimum depolarization loss while so-called aperture obstruction is considered calculation model. It can be seen that results closely follow evaluation both depolarized degree birefringent distribution of probe beam. We also find traditional...

Nowadays, the distributed fiber Raman amplifier (FRA) has become more and popular in long-haul systems, owing to its lower noise figures weaker nonlinear effects link. The critical issue FRAs is presence of various kinds noises their interactions with signal. However, existing channel models numerical solving methods can only partially describe how randomly interact This causes difficulties analyzing FRA precisely inconveniences for applications maintenance systems. In this paper, we propose...