Without complicated calculation, PSF at a certain depth can be interpolated from the PSF measured data at another depth with our PSF interpolation method. Significant similarities exist between the interpolated PSF and directly measured PSF. Our work is a successful attempt in using SPI to solve traditional optical problems.A simple and practical apparatus enabling repetition rate (frep) noise, carrier-envelope frequency (fceo) noise and nth optical comb mode (νn) noise spectra measurements with high precision is established. The frep and νn noise spectra are measured by a fiber delay line interferometer, while fceo noise spectrum is measured by an f-2f interferometer. We utilize this apparatus to characterize the noise performance of an Er-fiber optical frequency comb (OFC) and analyze the origin of dominant noise sources. Moreover, this apparatus provides a powerful tool for diagnosing noise dynamics intrinsic in mode-locked lasers and OFCs. To this end, we uncover the anti-correlation between frep and fceo noise as well as the impact of servo loops on noise characteristics in the stabilized OFC.In this work, we propose a new type of multispectral imaging system, named multispectral curved compound eye camera (MCCEC). The so called MCCEC consists of three subsystems, a curved micro-lens array integrated with selected narrow-band optical filters, an optical transformation subsystem, and the data processing unit with an image sensor. The novel MCCEC system can achieve multi-spectral imaging at an ultra-large field of view (FOV), and obtain information of multiple spectrum segments at real time. Moreover, the system has the advantages of small size, light weight, and high sensitivity in comparison with conventional multispectral cameras. In current work, we mainly focus on the optical design of the MCCEC based on the overlap of FOV between the neighboring clusters of ommatidia to achieve the multispectral imaging at an ultra-large FOV. https://www.selleckchem.com/products/pf-06952229.html The optical layout of the curved micro-lens array, narrow-band filter array and the optical relay system for image plane transformation are carefully designed and optimized. The whole size of the optical system is 93 mm × 42 mm × 42 mm. The simulation results show that a maximum FOV of about 120° can be achieved for seven-waveband multispectral imaging with center wavelengths of 480 nm, 550 nm, 591 nm, 676 nm, 704 nm, 740 nm, and 767 nm. The new designed MCCEC has a great potential as an airborne or satellite-born payload for real time remote sensing and thus paves a new way for the design of compact and light-weight spectral-imaging cameras with an ultra large FOV.We present a novel C-cavity concept for tunable lasers. The laser is based on a semiconductor optical amplifier (SOA), serving both as a gain medium as well as a modulator, and a chirped fiber Bragg grating (C-FBG) which acts as the end mirrors on both cavity ends. Driving the SOA with a pulse pair with variable delay enables wavelength tuning by targeting different regions in the C-FBG with the circulating pulse. The cavity design allows for wide tuning while maintaining a constant repetition rate, we show a tuning range of 35 nm -limited by the C-FBG's reflection bandwidth. Time-multiplexed operation with four different wavelengths is also demonstrated. Furthermore, the laser performance and dynamics under different operating conditions are analyzed and discussed.Silicon photonic platforms are of significant interest for a variety of applications that operate in the mid-infrared regime. However, the realization of efficient mid-IR modulators, key components in any integrated optics platform, is still a challenging topic. Here, an ultra-compact high-speed hybrid Si/VO2 modulator operating at a mid-IR wavelength of 3.8 μm is presented. Electrical properties of graphene are employed to achieve a reversible insulating-metal phase transition in VO2 by electrical actuation. The thermal characteristics of graphene are employed to improve the response time of the VO2 phase transition through speed up heating and dissipation processes, thus enhancing the modulation speed. Optical and thermal simulations show an extinction ratio of 4.4 dB/μm, an insertion loss of 0.1 dB/μm, and high modulation speed of 23 ns. A larger modulation depth as high as 10 dB/μm can be achieved at the cost of lower modulation speed.We report a cascaded optical fiber link which connects laboratories in RIKEN, the University of Tokyo, and NTT within a 100-km region using a transfer light at 1397 nm, a subharmonic of the Sr clock frequency. The multiple cascaded link employing several laser repeater stations benefits from a wide feedback bandwidth for fiber noise compensation, which allows constructing optical lattice clock networks based on the master-slave configuration. We developed the laser repeater stations based on planar lightwave circuits to significantly reduce the interferometer noise for improved link stability. We implemented a 240-km-long cascaded link in a UTokyo-NTT-UTokyo loop using light sent from RIKEN via a 30-km-long link. In environments with large fiber noise, the link instability is 3 × 10-16 at an averaging time of 1 s and reaches 1 × 10-18 at 2,600 s.The weak plasmonic coupling intensity in an aluminum (Al) nanostructure has limited potential applications in excellent low-cost surface-enhanced Raman scattering (SERS) substrates and light harvesting. In this report, we aim to elevate the plasmonic coupling intensity by fabricating an Al nanoparticle (NP)-film system. In the system, the Al NP are fabricated directly on different Al film layers, and the nanoscale-thick alumina interlayer obtained between neighboring Al films acts as natural dielectric gaps. Interestingly, as the number of Al film layers increase, the plasmonic couplings generated between the Al NP and Al film increase as well. It is demonstrated that the confined gap plasmon modes stimulated in the nanoscale-thick alumina region between the adjacent Al films contribute significantly to elevating the plasmonic coupling intensity. The finite-difference time-domain (FDTD) method is used to carry out the simulations and verifies this result.