Dental enamel is highly transparent at near-IR wavelengths and several studies have shown that these wavelengths are well suited for optical transillumination for the detection and imaging of tooth decay. We hypothesize that these wavelengths are also well suited for imaging cracks in teeth. Extracted teeth with suspected cracks were imaged at several wavelengths in the near-IR from 1300-1700-n...

A broadband and compact TE-pass/TM-stop polarizer is presented based on hybrid plasmonic grating (HPG) an x-cut Lithium-Niobate-on-isolator (LNOI) platform. By comprehensively analyzing the effects of metal width mode effective index, similarity, conversion, we demonstrate structure with a narrow layer. The simulation results indicate that length 9 ?m achieves extinction ratio over 20 dB within...

Shortwave infrared window (SWIR: 1000–1700 nm) represents a major improvement compared to the NIR-I region (700–900 in terms of temporal and spatial resolutions depths down 4 mm. SWIR is fast cheap alternative more precise methods such as X-ray opto-acoustic imaging. Main obstacles imaging are noise scattering from tissues skin that reduce precision method. We demonstrate combination vivo NIR-I...

A divergent microstructure was fabricated by complementary metal–oxide–semiconductor compatible processes on the central region of a Ge p–i–n photodetector to enhance residual tensile strain. tunable biaxial strain ?0.22%–1.01% achieved varying geometrical factors, and it confirmed Raman measurements finite element method simulations. The suspended germanium membranes absorption across C- L-ban...

This paper proposed angle measurement methods based on direct third harmonic generation (THG) in centrosymmetric crystals. The principles of the intensity-dependent and wavelength-dependent were illustrated. In this study, three prospective crystals two different phase-matching types investigated a wavelength range from 900 nm to 2500 nm. For method, dispersion-less was found 1700 2000 for α-BB...

A prismless ultrafast Cr4*:YAG laser has been designed and constructed. Intracavity dispersion in this laser is compensated through the use of double-chirped mirrors, in contrast to previous work, which used fused silica prisms. The resonator design for Kerr lens modelocking has been optimized through the use of numerical simulation programs, based on the ABCD transfer matrix formalism. Pulses ...

For this study, 21 samples of colorless octahedral diamonds (weighing 5.4–55.0 mg) from the Mir pipe (Yakutia) were investigated with photoluminescence (PL), infrared (IR), and electron paramagnetic resonance (EPR) spectroscopies. Based on IR data, three groups belonging to types IIa, IaAB, IaB selected their spectroscopic features analyzed in detail. The categories stones exhibited different c...

We propose a bi-layer 5-tip edge coupler in multilayer silicon nitride-on-silicon (SiN-on-Si) waveguide platform. The is used for the integration between monolithic 1550 nm laser and single-mode SiN waveguide. simulated coupling efficiency 92.8%. vertical 1-dB-loss misalignment tolerance as large 0.5 μm. Broad 1-dB-drop bandwidth (1338 to 1700 nm) small footprint (total length: 38...