Kruseralston4215

We investigate the conversion efficiency (CE) of soliton modelocked Kerr frequency combs. Our analysis reveals three distinct scaling regimes of CE with the cavity free spectral range (FSR), which depends on the relative contributions of the coupling and propagation loss to the total cavity loss. Our measurements, for the case of critical coupling, verify our theoretical prediction over a range of FSRs and pump powers. Our numerical simulations also indicate that mode crossings have an adverse effect on the achievable CE. JNJ-64619178 Our results indicate that microresonator combs operating with spacings in the electronically detectable regime are highly inefficient, which could have implications for integrated Kerr comb devices.The continuous wavelet transform (CWT) has been used in fringe projection profilometry (FPP) to recover a three-dimensional surface from a single-frame fringe. This Letter constructs a two-dimensional (2D) continuous complex wavelet employing a 2D real Mexican hat wavelet function, combined with the single-orthant analytical 2D Hilbert transform. The 2D complex wavelet has an asymmetric frequency envelope in the radial direction and the ability of direction selectivity, which results in better matching between the local fringe and daughter wavelets. We provide a complex wavelet construction model, present a theoretical analysis, and conduct experimental validation. The experiments demonstrate that the proposed method provides high phase accuracy in the single-frame FPP method.Compact fiber-to-chip couplers play an important role in optical interconnections, especially in data centers. However, the development of couplers has been mostly limited to standard single-mode fibers, with few devices compatible with multicore and multimode fibers. Through the use of state-of-the-art optimization algorithms, we designed a compact dual-polarization coupler to interface chips and dense multicore fibers, demonstrating, for the first time, coupling to both polarizations of all the cores, with measured coupling efficiency of -4.3dB and with a 3 dB bandwidth of 48 nm. The dual-polarization coupler has a footprint of 200µm2 per core, which makes it the smallest fiber-to-chip coupler experimentally demonstrated on a standard silicon-on-insulator platform.We present, to the best of our knowledge, the first demonstration of thermal, optical, and laser properties of YbGdScO3 for potentially efficient ultrashort pulse lasers. The stimulated emission cross section at 1025 nm (E//c) is 0.46×10-20cm2 with the emission band width of 85 nm, even broader than the well-known YbCaGdAlO4. It has quite a high thermal conductivity of 5.54W/(m⋅K) at 50°C, comparable with YbYAG. In the continuous-wave regime, the maximum output power of 13.45 W at 1063.9 nm was generated with the optical-to-optical efficiency of 63.3%. These results suggest that the YbGdScO3 crystal is a promising candidate for ultrashort pulse lasers.An effective method to calculate the statistical Mueller matrix (SMM) of suspended particles based on polarized light scattering is presented that takes advantage of the Stokes vectors measurement of individual particles. The calculation method of the SMM is derived based on statistics. Experimental results of Microcystis samples confirm that the SMM can characterize cells of different states. Then, pairwise contrast experiments indicate the great prospect of the SMM applied on the discrimination of suspended particles. It helps to find the optimal incident polarization state to discriminate suspended particles, and it has optimal discrimination ability. The parameter derived from the SMM can simultaneously discriminate particles including microalgae, microplastics, and sand-like particles.We propose a parabolic W-type thulium-doped fiber for the 1.7 µm high-energy femtosecond pulsed laser. Despite its attractive normal dispersion, the fiber offers high gain in 1.7 µm region thanks to its distributed short-pass filtering effect. With a proper dispersion management in an all-fiber chirped pulse amplification (CPA) scheme, we demonstrate so far the highest pulse energy of 128.0 nJ in a stable pulse of 174 fs in the 1.7-1.8 µm region, which marks above an order of magnitude improvement in pulse energy while exhibiting the shortest pulse duration among fiber-based CPA works at 1.7 µm. Hence, we provide a pathway to an energy scalable and efficient femtosecond laser at 1.7 µm via a compact and elegant all-fiber solution.In this paper, we provide an experimental proof-of-concept of this dynamic three-dimensional (3D) current manipulation through a 3D-printed reconfigurable meta-radiator with periodically slotted current elements. By utilizing the working frequency and the mechanical configuration comprehensively, the radiation pattern can be switched among 12 states. Inspired by maximum likelihood method in digital communications, a robustness-analysis method is proposed to evaluate the potential error ratio between ideal cases and practice. Our work provides a previously unidentified model for next-generation information distribution and terahertz-infrared wireless communications.Microfluidic techniques have emerged as promising strategies for a wide variety of synthetic or biological sorting. Unfortunately, there is still a lack of sorting with automatic and handy operation. In contrast to passively generated vortices, the thermocapillary vortices produced by temperature gradient have the advantages of flexible manipulation, stable strength, and simple integration. In this Letter, we present a device used for the pump-free separation of particles through vortices interaction without external fluidic control systems required for the majority of existing devices. Specifically, the device induces a different flow type upon the actuation of optical power, and the flow functions, such as simultaneous pumping and sorting, agree with stimulation results very well. More importantly, our developed sorting device can achieve separations by means of tunable cutoff diameter size. Therefore, this versatile device can be utilized to sort complex samples with the advantages of portability, user-friendly control, and automation.An angle-interrogated surface plasmon resonance (SPR) sensor based on a prism-coupled configuration has been extensively applied in biomedicine, environment monitoring, and food safety. Yet, the low sensitivity and low spatial resolution impede its further development. In this Letter, we investigated objective-coupled locally excited SPR for refractive index (RI) sensing with high sensitivity and high resolution. Through theoretical analysis, the SPR angle was retrieved from back focal plane imaging, which was highly correlated to the RI of the surrounding medium. Experimentally, a RI sensitivity of 77.41° refractive index unit (RIU)-1 was achieved with a detection range of 0.068 RIU when using glucose solutions for the demonstration. Furthermore, we acquired the spatial resolution of the configuration being 290 nm, and the RI measurement to a polydimethylsiloxane droplet with high spatial resolution was implemented. As a result, compared with the classical prism-coupled configuration, the locally excited SPR provides a method to achieve RI sensing with high sensitivity and high resolution.We experimentally demonstrated a high repetition rate harmonic mode-locked fiber laser with a high signal-to-noise ratio (SNR) and super mode suppression ratio. A novel approach using a laser with a high fundamental repetition rate and low harmonic order was presented. 2.5 GHz harmonic mode-locking from an Yb-doped fiber laser was realized with a short cavity length corresponding to a 167 MHz fundamental repetition rate. The laser operated at anomalous net dispersion regime and generated soliton-like pulses at 1050 nm. At the harmonic order of 15th, the laser had a stable output of 773 fs at 2.5 GHz with the average power of 48 mW under a subwatt pump power of 406 mW, and the time jitter was 2 ps. A high RF SNR over 70 dB was measured. A super mode suppression ratio was confirmed larger than 60 dB. This is, to the best of our knowledge, the highest SNR and super mode suppression ratio achieved in harmonic mode-locked fiber lasers with an over 2 GHz repetition rate.This publisher's note contains corrections to Opt. Lett.46, 2738 (2021)OPLEDP0146-959210.1364/OL.423745.We report the theoretical discovery of a new effect, namely, the effect of magnetically induced transparency. The effect is observed in a magnetically active helically structured periodical medium. Changing the external magnetic field and absorption, one can tune the frequency and the linewidth of the transparency band.Time of flight and photometric stereo are two three-dimensional (3D) imaging techniques with complementary properties, where the former can achieve depth accuracy in discontinuous scenes, and the latter can reconstruct surfaces of objects with fine depth details and high spatial resolution. In this work, we demonstrate the surface reconstruction of complex 3D fields with discontinuity between objects by combining the two imaging methods. Using commercial LEDs, a single-photon avalanche diode camera, and a mobile phone device, high resolution of surface reconstruction is achieved with a RMS error of 6% for an object auto-selected from a scene imaged at a distance of 50 cm.Multimodal nonlinear microscopy combining third-harmonic generation (THG) with two- and three-photon-excited fluorescence (2PEF and 3PEF) is shown to provide a powerful resource for high-fidelity imaging of nucleoli and nucleolar proteins. We demonstrate that, with a suitably tailored genetically encoded fluorescent stain, the 2PEF/3PEF readout from specific nucleolar proteins can be reliably detected against the extranucleolar 2PEF/3PEF signal, enabling high-contrast imaging of the key nucleolar ribosome biogenesis components, such as fibrillarin. THG is shown to provide a versatile readout for unstained nucleolus imaging in a vast class of biological systems as different as neurons in brain slices and cultured HeLa cells.Temperature-dependent characteristics of GeSn/Ge multiple-quantum-well (MQW) photoconductors (PCs) on silicon substrate were investigated. The high quality GeSn/Ge MQW epitaxial structure was grown on a silicon substrate using low temperature molecular beam epitaxy techniques with atomically precise thickness control. Surface-illuminated GeSn/Ge MQW PCs were fabricated using complementary metal-oxide-semiconductor-compatible processing and characterized in a wide temperature range of 55-320 K. The photodetection range was extended to λ=2235nm at T=320K due to bandgap shrinkage with Sn alloying. Measured spectral responsivity was enhanced at reduced temperatures. These results provide better understanding of GeSn/Ge MQW structures for efficient short-wave infrared photodetection.We developed a thermo-optically controlled nonmechanical optical beam scanner using a Si photonic crystal slow-light waveguide with a diffraction grating to achieve on-chip light detection and ranging (LIDAR). This Letter applies pre-emphasis signals to the thermo-optic control, and the cutoff frequency increases to 500 kHz. Observing the beam scanning in the space-time domain showed that the turn-on and turn-off times of the scanner for a rectangular drive voltage were 10 µs and reduced to 2.7 µs when the pre-emphasis signals were optimized. This new, to the best of our knowledge, result enables a frame rate of 29 fps for 12,800 resolution points in LIDAR.