This PDF file contains the front matter associated with SPIE Proceedings Volume 11826, including the Title Page, Copyright Information, and Table of Contents.

In this work, a low-loss near-zero dispersion polypropylene fiber is designed for signal transmission at the carrier frequency of 128 GHz. An infinite 3D printing technique is explored to continuously fabricate the proposed fiber without length-limit. The in-depth theoretical and experimental comparisons between the two fibers printed using standard and infinite 3D printers are introduced in detail. Particularly, transmission losses of 2.39 dB/m and 5.57 dB/m have been experimentally demonstrated for the two fibers at 128 GHz. Furthermore, for the two fibers with the corresponding lengths of 2 m and 1.6 m, signal transmission with bit error rates far below the forward error correction limit (10-3) was clearly observed. Error-free transmission is realized at the bit rates up to 5.2 Gbps for the standard 3D printed fiber at the length of 1.5 m.

In order to study the new holographic recording medium, four kinds of photopolymer materials containing TMPTA monomers are studied. The three-dimensional interference fringe information was successfully recorded in the photopolymer film samples, which proved that it has good holographic recording and high resolution ability. The experimental results show that when the recording angle is 30°, the diffraction efficiency is as high as 93.5%@532nm and the refractive index modulation is as high as 3.07×10^-3. As a holographic recording medium, it has high resolution ability and high diffraction efficiency, the material is possible suitable for permanent storage of holograms and big data, besides it has strong advantages and potential applications in the large-scale 3D display, big data storage, holographic anticounterfeiting, holographic printing and other fields.

In order to study a new holographic recording medium, this paper prepares a kind of holographic photoinduced polymer material based on a double monomer and a composite photoinitiator. Add different photoinitiator, such as red bengal (RB), titanium (irgacure 784, Ti) and a mixture of the two in the photopolymer materials, and then perform holographic exposure. We found that the compound photoinitiator improved the diffraction efficiency, light sensitivity, and transmittance to some extent compared with a single photoinitiator. Combined with the diffusion kinetics, we studied the effects of the two kinds of photoinitiators on the photoinduced polymers, and the ratio of the composite photoinitiators was optimized. The holographic parameters such as diffraction efficiency under different exposure intensities, different exposure time, different thickness and different wavelength are tested, it is shown that the exposure conditions have a great influence on the diffraction efficiency. At the same time, this material is sensitive to both green light and red light. The experiment results show that the reconstructed image is clear and bright, which indicates that the photoinduced polymer is suitable for dual-wavelength multiplexing holographic storage.

We report on organic-inorganic nanocomposites with combined properties of quantum cutting and down shifting of solar UV spectrum. They cut a single high energy UV photon of solar radiation in two near-IR (NIR) low energy photons and use the energy of the UV photon to produce low energy visible photons. The applications include solar spectrum down convertors and luminescent solar concentrators (LSCs). The nanocomposites were made of organic hosts filled the nanoparticles of Lanthanide doped fluoride phosphor NaYF₄:Yb³⁺, Er³⁺. As an organic host for the nanoparticles in an LSC simulator 1-Propanol was used. The particles of the synthesized phosphor powder were ball-milled to an average size of~ 200-nm. The LSC filled with the phosphor nanocolloid produced 130% more electric power than in case of pure 1-Propanol. This effect was not observed when the LSC was illuminated with an incandescent light bulb with no UV component in its radiation spectrum. The LSC performance was thus due to down shifting and quantum cutting of the UV spectral component of solar radiation by the phosphor nanoparticles into visible and NIR radiation matching the spectral response of the silicon PV solar cells. The results are of interest for green solar power.

In this study, we report an experimental analysis on the triggering performance of a GaAs photoconductive semiconductor switch (PCSS) array. Resistors in parallel are known to outperform a single resistor in terms of heat management, current manipulation, wattage control, etcetera. Reconstructing the shape of resistors to obtain such a performance can impose limitations that inhibit it to compete with its parallel counterpart. The creation and synchronous triggering of a PCSS array may also result in an improved current and triggering performance which can be useful for high-speed nanosecond applications.

In this paper, we present 2-dimensional (2D) large capacity time-division multiplexing (TDM) laser beam combining technique by potassium tantalate niobate (KTN) electro-optic (EO) beam deflectors. The use of the 2D TDM approach in laser beam combining brings the following key advantages: (1) a large multiplexing capacity compared to 1-dimensional combining, (2) high spatial and spectral beam quality (the combined laser beam has the same spatial and spectral beam profile as the initial individual laser beams), and (3) independency of the phase fluctuation of individual laser beams due to the nature of incoherent laser beam combining. To demonstrate an implementation of 2D beam combining, we recorded the beam after passing KTN crystals with a CCD camera. Our result shows beam combining with a high beam quality, leading to the higher capacity of the TDM technique, which can play a crucial role in applications such as highenergy lasers, laser manufacturing, and large-capacity high-speed laser manufacturing (3D printing).

Rugged optics are in ever-increasing demand as technologies advance and user adaptation expands. Traditional solutions, such as fused silica or glass, fail to withstand harsh laser environments, causing manufacturers to look for more robust solutions. Additionally, bandwidth and power ranges must also be considered when choosing optics for new laser-based instruments. Advancements in the growth, manufacture and finishing of high transmission sapphire windows have evolved to meet these new applications and environments.

Currently, the power handling capability of optical fibers is primarily limited by glass damage thresholds and induced nonlinearities, including stimulated Brillouin scattering and stimulated Raman scattering. In order to mitigate unwanted nonlinear effects, a majority of high power delivery fibers have increased core sizes, which are generally used near the threshold of multimode operation. Under high power, thermal changes lead to transverse mode instabilities which degrade the overall beam quality. We have been investigating hollow core fibers based on the anti-resonant effect (ARHCF) due to their excellent guiding properties, such as low loss, large core sizes, wide transmission windows, and significantly increased optical nonlinearity and damage thresholds. Anti-resonant HCFs have significantly simpler designs compared to other microstructured fibers, namely photonic bandgap fibers, which leads to more flexibility and less complex fabrication. An ARHCF design was optimized in Comsol Multiphysics for single mode operation, low propagation loss, and low bending loss. The ARHCF was fabricated at the University of Central Florida. Initial testing has shown that power handling up to 170 W input, 0.7 GW/cm² at the fiber facet is possible with no damage to the fiber.

We propose a volume holographic optical element (VHOE) used as an objective turret in a lensless digital holographic microscope. It also served as a reference wave guide to reduce the volume of the system. For further optimization of resolution performance, it used a spherical wave in the object light of the VHOE, which served as the reference light of the microscope. Another sheared spherical wave was used to illuminate the sample. The optimized VHOE increased the spatial resolution of the record signal effectively. Furthermore, the change of spherical wave distance leads to the change of imaging magnification.

We discuss the trade-off caused by the system parameters, and the performance degradation caused by the angular momentum of the rotational motor for shifting multiplexing. We also propose applying phase-integrated double-frequency grating shearing interferometer (PI-DFGSI) to makes the reading with moving disc being possible, and thus improves the system performance.

Silicon-on-Insulator (SOI) waveguides are suitable for photonic integrated design for communication as well as sensing due to its various advantageous features. Initial research on SOI waveguide showed that light as a wave can be confined inside high refractive indexed bulk silicon rectangular waveguide. Later, research reported by researchers working on silicon nanowire waveguide suggests that wave can also be guided in low refractive index (RI) region, mainly inside the gaps between high RI materials. The working phenomena and application for its sensing capacity is related to a number of factors, which need full in-depth understanding. This study started with the comparison of mode field propagation and sensing behaviour of both high refractive indexed guided bulk rectangular waveguide and low refractive indexed guided nanowire waveguide. This study suggests that both, bulk high RI waveguide and nanowire low RI waveguide are supporting hybrid modes of quasi-TE nature. Results indicate that interaction of sensing analyte is significant in nanowire waveguide and negligible in bulk rectangular waveguide. Waveguide responses were analyzed using finite element method-based boundary mode analysis. The result showed that the surface sensing is dominant and to illustrate the role of surface interacting with analyte, the effect of functionalization layer coverage over the surface of silicon wires is investigated using waveguide confinement factor. These results suggest that full cover of functionalization layer is having more interaction towards sensing analyte. On this basis, the concept of functionalization layer over waveguide sensing surface should be taken into account when designing a label-free surface sensing optical device.

In this work, we present simultaneous and sensitive detection of methane and ethane at ~3.34 µm using a 15-meteres long self-fabricated silica ARHCF and Wavelength Modulation Spectroscopy technique. The ARHCF was filled with a mixture of 10 ppmv and 20 ppmv ethane and methane, respectively via air-tight housings placed at both fiber end-facets. The gas molecules were excited using a self-built continuous wave Difference Frequency Generation source which radiation was coupled into the gas-filled ARHCF. The ARHCF-aided gas sensor reached a minimum detection limit at parts-per-billion by volume level, confirming the suitability of the proposed approach for trace-gas sensing.

Detection of Nitric Oxide at 5.26 µm is performed using photothermal interferometry and a 25 cm-long antiresonant hollow-core fiber as an absorption cell, reaching a minimum detection limit of 11 ppb for 144 seconds averaging. The proposed configuration shows the full potential of combining novel hollow-core fibers with the photothermal detection techniques, which allows separating the pump and the probe part of the sensor.

We present a proof-of-concept of the ARHCF-assisted gas molecules detection setup applying a non-wavelength modulation differential optical absorption spectroscopy (DOAS) technique to reduce an intermodal interferences effect and the compensation of changes in laser beam propagation parameters through ARHCF air-core. Toggled intensities of two air-core propagated laser beams have closely spaced wavelengths, while only one coinciding with targeted absorption line of acetylene at 1532.83 nm (~6524 cm-1). The difference in detected light intensities is used to determine a targeted gas concentration. Self-designed boxcar average unit allowed to 50 000 times/sec signals averaging, providing a minimal detection limit equal to 2.7 ppmv at 10s integration time.

Optical interferometry is widely used for various sensing applications. In general, it uses conventional Gaussian beam to generate interference pattern. Recent literature has shown that one can use non-diffracting Bessel beam to generate interference pattern and can exploit the non-diffracting property of the beam to overcome some sample-to-source distance related issues. This article demonstrates the use of a packaged optical fiber negative axicon probe generating quality Bessel beam for common-path Bessel beam interferometry to measure the refractive index of a small volume liquid sample. The refractive index measuring device consists of a broadband Superluminescent diode (SLD) source, a circulator, and a spectrometer. The packaged probe is connected to a broadband SLD source through an optical circulator, and a drop of microliter liquid sample is placed on the packaged probe's head. The reflected light from the glass-liquid interface couples to the axicon probe and interferes with the reference beam generated at the axicon's air- glass interface. The interference spectra are recorded in a spectrometer through the circulator. The interference spectrum is further processed in MATLAB by applying fast Fourier transform (FFT) to calculate power from the respective interface and solve the Fresnel equation for refractive index measurement. The refractive index of sucrose solutions is measured for a small sample volume ~ 2 µL at different concentrations for testing the suitability of the design. We have also measured the refractive index of bovine serum albumin (BSA) solution. This sensing platform shows promising applications in biomedicine for monitoring of various bio sample concentrations. It can work on remote sample and with longer working distance.