An optical true time delay line (OTTDL) is a fundamental building block for signal processing applications in microwave photonics and communications. Here, we experimentally demonstrate an index-variable OTTDL based on array of 40 subwavelength grating (SWG) waveguides silicon-on-insulator. Each SWG waveguide the 34 mm long arranged serpentine manner; average incremental between about 4.7 ps, total first last approximately 181.9 ps. The occupies chip area <mml:math...

We numerically investigate the operational principle and performance of stimulated Brillouin scattering based multiple microwave frequency signals measurement. The unknown are processed specially to generate a gain region which is measured by phase modulation amplitude converting. By sweeping vector network analyzer, both single frequencies measurement can be achieved. loss spectrum generated one pumps fully compensated other pump, increases range from 2νB 4νB.

We proposed a dual-chirp microwave photonic radar based on compressive sensing for distance and velocity measurement. This can generate different chirp linear frequency modulated (LFM) signals using dual-parallel Mach-Zehnder modulator (DPMZM). In the receiving part, dual-drive (DDMZM) (MZM) are cascaded optical mixing de-chirp processing with pseudo-random bit sequence (PRBS). Then mixed signal be gathered by an analog-to-digital converter (ADC) at sampling rate that is well below Nyquist...

A single passband microwave photonic filter with ultrawide tunable range based on stimulated Brillouin scattering is theoretically analyzed. Combining the gain and loss spectrums, tuning 44GHz obtained without crosstalk by introducing two pumps. Adding more pumps, Tuning multiplying multiplication factor equaling to total quantity of pump can be achieved, which has potential application in millimeter wave wireless communication systems.

A flux-controlled memristor characterized by smooth cubic nonlinearity is taken as an example, upon which the voltage—current relationships (VCRs) between two parallel memristive circuits — a and capacitor circuit (the MC circuit), inductor ML circuit) are investigated. The results indicate that VCR these closely related to parameters, frequency amplitude of sinusoidal voltage stimulus. An equivalent model built, simulations experimental measurements both performed, verify theoretical...

We present a novel and simple scheme for photonic generation of millimeter-wave ultrawideband (UWB) signal free low-frequency components that is implemented by using stimulated Brillouin scattering (SBS)-based frequency-doubling method. A dual-parallel Mach-Zehnder modulator incorporated to generate appropriate optical sidebands an carrier carrying the UWB signal. Then single-sideband modulation realized based on successive SBS frequency shifting process. Eventually, upconverted twice radio...

Enhanced Sobel operators were proposed to identify the scattering spectrum based on a Brillouin optical time-domain analysis (BOTDA) system and experimentally demonstrated. To best of our knowledge, this is first time use enhanced in BOTDA system. The approach regarded as an image, where gain could be edges was sharpened more, better denoising effect achieved by operators. Not only that, novel method omit Lorentz fitting make recognition more intuitive fast regardless multiple points caused...

A thermo-optical variable optical attenuator (VOA), consisting of three cascaded three-waveguide directional couplers, was designed on Silicon-On-Insulator (SOI) wafer. Thermo-optical dynamic, static analysis and propagation characteristic simulation at the wavelength 1550 nm were presented. The dynamic attenuation range from 0.14 dB to 50 achieved by a refractive index (RI) variation: 0 5.55 x 10(-3), (the corresponding temperature 30 degrees C). response time about 5 micros, which...

The cantilever is fabricated on (110) silicon wafer by anisotropic wet etching method in KOH; the sidewall of {111} plane, and it vertical to substrate. convex corner undercut, concave structure corresponds with design. mechanism undercutting explained theory covalent bond density.

Silicon-based torsion-beam 8×8 optical switch array are designed and fabricated with bulk silicon micromachining technology. Torsion beams cantilever reflective micromirror situated on the same wafer (1 1 0) silicon. During fabricating torsion beam actuating structure, etched hillocks plane obstacles to achieve smooth beam. It is put forward reasonable ratios mixtures of HF, HNO3 CH3COOH improve processes structure. The slanted under electrodes that can reduce voltage tilting 1) by wet...

We designed a microwave (MW) photonics phase shifter, consisting of Fabry-Perot filter, modulation region (PMR), and distributed Bragg reflectors, in silicon-on-insulator rib waveguide. The thermo-optics effect was employed to tune the PMR. It theoretically demonstrated that linear MW shift 0-2pi could be achieved by refractive index variation 0-9.68x10(-3) an ultrawideband (about 38?GHz-1.9?THz), corresponding tuning resolution about 6.92 degrees / C. device had very compact size. easily...

In this paper, we present a microwave photonic filter bandpass with narrow bandwidth and high quality (Q) factor is presented which of 7.8 MHz, gain response 24 dB, Q 2412.This performance achieved through tailoring one Brillouin spectrum by two loss spectrums.By precise control the individual pump power frequency, narrowed generated.We achieve mathematical formulation Stimulated scattering (SBS) relative frequency shift SBS pumps ratio, resulting in parameters resolution narrowest leading...

We propose a microwave photonic compressive sensing radar for distance and velocity measurement. First, de-chirped signal that carries or information is extracted between the transmitted received signals in proposed system. Then it mixed with pseudo-random bit sequence optical domain using Mach–Zehnder modulator. After that, can be acquired by photodetector an analog-to-digital converter (ADC) at sub-Nyquist sampling rate. Finally, reconstruction algorithm used to recover signal. In our...

A photonics-based channel bandwidth tunable microwave frequency measurement (MFM) is analyzed and verified, which implemented based on the principle of frequency-to-phase-slope mapping (FTPSM) in stimulated Brillouin scattering (SBS). The spectrum-controlled phase shift curve created by using an optical comb (OFC) pump instead a single pump. As result, response superimposed to further realize flexible adjustable bandwidth. Meanwhile, thanks relationship between OFC unknown signal, can be...

We report on simultaneous magneto-optical trapping of fermionic 40K and bosonic 87Rb atoms. This trap is the first step towards quantum degenerate fermi gas 40K. Laser lights for two-species (MOT) are generated from diode lasers tapered amplifier. The enriched dispenser utilized in experimental setup. obtain up to 107~108 108~109 atoms respectively steady-state single-species MOT.

We have developed an enriched 40K source used in 40K–87Rb atomic mixture cooling experiment. The is a home-made dispenser which releases atoms by the redox reaction between KCl and calcium. It efficient easy to be made used. collect 107~108 collection magneto-optical trap. With this dispenser, we perform quantum degenerate Fermi gas