A liquid-filled PCF temperature sensor, exhibiting high performance and a straightforward design, is proposed here. It is implemented using a SMF-PCF-SMF (single-mode fiber) sandwich architecture. Modifications to the structural parameters of the PCF allow for the attainment of superior optical properties compared to conventional optical fibers. Therefore, the fiber transmission mode demonstrates a more perceptible change in response to minor shifts in external temperature conditions. By altering the fundamental structural parameters, a novel PCF structure including a central air cavity is created, demonstrating a temperature sensitivity of negative zero point zero zero four six nine six nanometers per degree Celsius. Temperature-sensitive liquid material filling of PCF air holes leads to a more pronounced reaction of the optical field to temperature fluctuations. The chloroform solution's substantial thermo-optical coefficient allows for the selective infiltration of the resulting PCF. Upon comparing different filling strategies, the calculated results demonstrated the ultimate temperature sensitivity of -158 nanometers per degree Celsius. The designed PCF sensor's simple design, combined with its high-temperature sensitivity and good linearity, presents compelling practical application potential.

A multidimensional characterization of femtosecond pulse nonlinearity in a tellurite glass multimode graded-index fiber is presented. A quasi-periodic pulse breathing, exhibiting novel multimode dynamics, demonstrated a recurrent pattern of spectral and temporal compression and elongation, contingent upon alterations in input power. This phenomenon results from the power-dependent shaping of the distribution of excited modes, which consequently alters the effectiveness of the nonlinear processes taking part. Thanks to the modal four-wave-mixing phase-matching facilitated by a Kerr-induced dynamic index grating, our results offer indirect evidence for periodic nonlinear mode coupling taking place within graded-index multimode fibers.

A study of the second-order statistical characteristics of propagation of a twisted Hermite-Gaussian Schell-model beam in a turbulent atmosphere is undertaken, which includes the spectral density, degree of coherence, root mean square beam wander, and orbital angular momentum flux density. Citric acid medium response protein Our findings demonstrate that atmospheric turbulence and the twisting phase contribute to the prevention of beam splitting during the course of beam propagation. Yet, the two determining aspects have contrasting implications for the advancement of the DOC. virus-induced immunity Propagation through a twist phase maintains the DOC profile's integrity, but turbulence causes the DOC profile to deteriorate. Numerical examples also explore the influences of beam parameters and turbulence on beam wandering, highlighting the potential for reducing beam wander through modification of the beam's initial settings. The conduct of the z-component OAM flux density, in the vacuum of space and within the atmospheric sphere, is meticulously studied. Within the beam's cross-section, under turbulent conditions, the OAM flux density's direction, without considering the twist phase, undergoes a sudden inversion at each point. The inversion's dependency rests solely on the beam's initial width and the turbulence's strength; this consequently offers a practical method for assessing turbulence intensity by measuring the propagation distance where the OAM flux density reverses its direction.

Terahertz (THz) communication technology is set to experience innovative breakthroughs due to the burgeoning field of flexible electronics. While vanadium dioxide (VO2)'s insulator-metal transition (IMT) presents excellent application potential for THz smart devices, flexible state THz modulation properties remain largely unreported. Utilizing pulsed-laser deposition, we deposited an epitaxial VO2 film onto a flexible mica substrate, and then scrutinized its THz modulation characteristics under varying degrees of uniaxial strain encompassing the phase transition. Observation indicates that the depth of THz modulation rises under compressive stress and diminishes under tensile stress. ODN 1826 sodium The uniaxial strain is a critical factor determining the phase-transition threshold. The phase transition temperature's responsiveness to uniaxial strain is pronounced, reaching a rate of change of about 6 degrees Celsius per percentage point of strain in temperature-induced phase changes. The optical trigger threshold of laser-induced phase transitions experienced a 389% decrease under compressive strain, but a 367% increase under tensile strain, in comparison with the initial, uniaxially unstrained state. Uniaxial strain-induced low-power THz modulation is demonstrated in these results, revealing significant implications for the use of phase transition oxide films in flexible THz electronics.

Polarization compensation is crucial for non-planar image-rotating OPO ring resonators, differing from their planar counterparts. Maintaining the phase matching condition during each cavity round trip is critical for non-linear optical conversion within the resonator. Our research investigates the impact of polarization compensation on the performance of two non-planar resonator types, RISTRA featuring a two-image rotation and FIRE employing a fractional image rotation of two. The RISTRA method shows no sensitivity to variations in mirror phase shifts, contrasting with the FIRE method's more complex dependency of polarization rotation on the mirror phase shift. The adequacy of a single birefringent element for polarizing compensation in non-planar resonators, exceeding the capabilities of RISTRA-type structures, is a subject of ongoing debate. Even fire resonators, under experimentally realizable conditions, demonstrate adequate polarization compensation using a single half-wave plate, according to our findings. The polarization of the OPO output beam, when using ZnGeP2 nonlinear crystals, is investigated experimentally and numerically to validate our theoretical analysis.

The transverse Anderson localization of light waves is demonstrated in this paper inside a 3D random network optical waveguide, formed by a capillary process within an asymmetrical fused-silica fiber. Naturally occurring air inclusions and silver nanoparticles within a rhodamine dye-doped phenol solution give rise to the scattering waveguide medium. Optical waveguide disorder is dynamically adjusted to govern multimode photon localization, suppressing unwanted extra modes and yielding a single, strongly localized optical mode at the desired emission wavelength of the dye molecules. Time-resolved single-photon counting is applied to examine the fluorescence dynamics of dye molecules embedded in Anderson-localized modes within the disordered optical medium. The dye molecules' radiative decay rate experiences a pronounced enhancement, reaching a factor of approximately 101, upon coupling into a specific Anderson localized cavity within the optical waveguide. This achievement serves as a pivotal advancement in investigating the transverse Anderson localization of light waves within 3D disordered media, enabling manipulation of light-matter interaction.

The precise determination of satellite 6DoF relative position and pose change, under controlled vacuum and temperature conditions on the ground, is crucial for ensuring the accuracy of satellite mapping in space. In pursuit of high accuracy, high stability, and miniaturization for a satellite's measurement system, this paper proposes a laser-based technique capable of simultaneously measuring the 6 degrees of freedom (DoF) of relative position and attitude. Focused on miniaturization, a measurement system was developed, and an accompanying measurement model was established. Through theoretical analysis and OpticStudio simulations, the issue of error crosstalk between 6DoF relative position and pose measurements was addressed, leading to enhanced measurement accuracy. Next, laboratory experiments and field tests were meticulously carried out. Our experimental evaluation of the developed system revealed that the relative position accuracy was 0.2 meters and the relative attitude accuracy was 0.4 degrees, constrained by measurement ranges of 500mm along the X-axis and 100 meters along the Y and Z axes. Subsequent 24-hour stability tests confirmed values superior to 0.5 meters and 0.5 degrees respectively, meeting the demands of satellite ground-based measurements. The satellite's 6Dof relative position and pose deformation were obtained via a thermal load test, following the successful on-site implementation of the developed system. This innovative measurement system, crucial for experimental satellite development, further offers a method for high-precision 6DoF relative position and pose measurement between two points.

High-power mid-infrared supercontinuum (MIR SC) generation, spectrally flat, is showcased, achieving an unprecedented output power of 331 W and a power conversion efficiency of 7506%. A 2-meter master oscillator power amplifier system, incorporating a figure-8 mode-locked noise-like pulse seed laser and dual-stage Tm-doped fiber amplifiers, is responsible for pumping the system at a repetition rate of 408 MHz. Cascading a ZBLAN fiber of 135-meter core diameter by direct low-loss fusion splicing created spectral ranges of 19-368 m, 19-384 m, and 19-402 m. Associated average power outputs were 331 W, 298 W, and 259 W, respectively. Each one, as far as our knowledge extends, produced the maximum output power, all functioning under a unified MIR spectral band. This all-fiber MIR SC laser system, boasting high power, features a relatively simple design, high efficiency, and a consistent spectral distribution, highlighting the benefits of a 2-meter noise-like pulse pump for generating high-power MIR SC lasers.

Within the scope of this study, (1+1)1 side-pump couplers, composed of tellurite fibers, were produced and studied. Ray-tracing models underpinned the optical design of the coupler, with experimental outcomes providing the validation.