The performance of intense Bessel femtosecond pulse propagation in dispersive medium is investigated. Water is chosen as the Kerr medium with large dispersion. We find that within the dispersion length, the temporal profile integr

Nonlinear processes associated with terahertz radiation generated via optical rectification from undoped GaP crystal, including second harmonic generation (SHG) and multiphoton absorption processes, are examined. Experimental resu

Terrorism has become an international problem in recent years as evidenced by toxins mailed through the post, liquid explosives planted in airplanes, and so on. Clearly, the security screening of packing materials is highly requir

The characteristics of terahertz radiation from an n-type InN excited by femtosecond laser pulses tunable from 750 to 840 nm are experimentally studied. Terahertz emission from InN is closely bound up with the Dember effect. Terah

Terahertz (THz) wave transmission through a thin metal film with periodic arrays of subwavelength rectangular holes is investigated systematically. The roles of the waveguide resonances and surface plasmon polaritons (SPPs) in ext

A new scheme to realize terahertz (THz) radiation generation, as well as high-speed THz modulation, for future high-speed THz communication systems, is proposed and discussed. The proposed experimental scheme includes two elementa

The electro-optic (EO) technique used in the terahertz spectral technology is described. Response functions—which are used to describe the EO detecting efficiency—of five types of cubic EO crystals are calculated. Based on these r

We investigate the optical response of silicon-based VxOy film for terahertz (THz) transmission. We find that absorption of the THz wave by the film can be controlled by laser excitation. Using THz time-domain spectroscopy (THz-TD

The transit characteristics of gain electrons in the dynamic electric field in one micro-channel, the relation of the temporal resolution, and the gating electric pulse are discussed in detail. The simulation analyses provide guid

Fulgide, a kind of thermally irreversible photochromic compound, can be used for polarization holographic recording owing to its photoinduced anisotropy and photochromic property under the irradiation of linear polarization light.

The characteristics of air plasma are studied using laser-induced breakdown spectroscopy at room temperature in air at atmospheric pressure. The electron temperature of 20796 K is determined using the Boltzmann plot method with si

The detonation temperature is measured both theoretically and experimentally by means of a complementary metal oxide semiconductors (CMOS) image sensor. An experimental system of multiwavelength temperature measurement based on CM

We report on a new technique of mutual injection phase-locking fiber-laser array. This technique uses a 45o beam splitter as coupling device. Injection phase-locking process of the fiber-laser array is simulated and analyzed. Resu

An all-digital design method consisting of a laser drive circuit for gradually modulating the frequency, pulse width, and amplitude of the output of semiconductor laser is demonstrated. Field programmable gate arrays (FPGAs) and a

To achieve high peak current with narrow pulse width, the circuit model is analyzed based on a fast and high-power metallic oxide semiconductor field effecttransistor (MOSFET) as the high speed switch of the resistor-capacitor (RC

High-speed dynamic spectrum data of transient detection has become the major means of access to transient information. However, in terms of the characteristic of spectral data excessiveness and transience in the dynamic spectral d

Time-resolved diagnosis of the transient process using X-ray frame cameras (XRCs) is an important means in inertial confinement fusion (ICF) experiments. The sensitivity of the photocathode is a key parameter of the entire camera

A novel optical fiber evanescent-wave (EW) sensing platform combining a taper and a refractive index (RI) gel residue is proposed. The platform includes two identical large core multimode fibers perpendicularly positioned to each

The features of Moire fringe generated by overlapping a circular and a linear grating are studied. Given that the pitch of circular grating is a and that of linear grating is P, the shapes of the Moire fringe that they form are hy

Core/shell CdSe/ZnS quantum dots (QDs) are synthesized by thermal deposition using cadmium oxide and selenium as precursors for a hot lauric acid and hexadecylamine trioctylphosphine oxide hybrid. The CdSe/ZnS QDs show high photol

In order to improve the burn-resistant property of titanium (Ti) alloy, Ti-molybdenum (Mo) burn-resistant alloyed layer is coated onto the Ti6Al4V substrate with the double glow plasma surface alloying technology by permeating the

Chemical oxygen demand (COD) is a synthetic indicator that represents the degree of organic pollution in water. Compared with the conventional wet chemical method, near-infrared (NIR) transmission and ultraviolet (UV) absorbance m

A portable near-infrared (NIR) spectroscopy analyzer is developed for rice wine analysis. The analyzer is composed of a lamphouse, a temperature-controlled sample chamber, a mini-spectrometer, and a control unit. The mini-spectrom

We propose a three-dimensional chiral metamaterial consisting of arrays of multi-layered mutually twisted sandwich metallic spirals. Such structure exhibits a negative refractive index at terahertz frequencies for its chirality. T

A metamaterial (MM) absorber is very attractive in the terahertz (THz) regime for its potential applications as a bolometer and thermal emitter. In this letter, we propose a transmission line model for the MM absorber in order to

We present a thermal active control over terahertz (THz) extraordinary transmission induced by a plasmon in a periodic subwavelength holes array and a patch array. Both arrays consist of high transition temperature YBCO supercondu

We present a systematic study of freestanding terahertz (THz) metamaterials fabricated on Mylar film by self-aligned photolithography. THz time-domain spectroscopy (THz-TDS) transmission measurements and numerical simulations reve

A new data-acquisition method based on the less movement of the time-delay stage is designed. The method can clearly reduce the time used in the entire imaging process in terahertz pulse imaging. According to the experimental resu

Terahertz time-domain spectroscopy (THz-TDS) is a new coherent spectral technique to measure transmission spectra and analyze the spectral characteristics of samples. In this letter, the transmission spectra of edible pigments in

The transmission spectra of methylparaben, ethylparaben, propylparaben, and butylparaben in the range of 0.2–2.5 THz are measured using terahertz time-domain spectroscopy (THz-TDS). Their refractive index and absorption spectra ar

The field of terahertz (THz) science and technology has achieved significant progress over the last decades. Research interest focuses on THz spectroscopy and imaging. The signal-to-noise ratio (SNR) of the THz system is of great

The frequency-dependent absorption coefficients and refractive indexes of three selected pour point depressants (PPDs) are extracted within the spectral range of 0.2–2.5 THz using terahertz time-domain spectroscopy (THz-TDS). The

In this letter, we employ terahertz time-domain spectroscopy (THz-TDS) technology to measure the THz absorption spectrum and refractive index of benzoic acid at room temperature. Linearity combination of atomic orbital (LCAO) with

We report on the far–infrared optical properties of melamine characterized by terahertz time–domain spectroscopy (THz–TDS). Transmission measurement reveals three low–frequency vibration modes at 1.99, 2.25, and 2.61 THz, which ma

We observe the instantaneous frequency and amplitude modulations of the C-C stretching mode with a central frequency of 1343 cm?1 in a poly (substituted thiophene) using 6.3 fs laser pulses by the method of real-time vibrational s

Cylindrical vector beams are described by the representation formalism of finite electromagnetic beams in free space. This is achieved by factorizing the field vector into a mapping matrix and a Jones-like vector. The vectorial pr

The pulse broadening and communication capacity in atmospheric turbulent and disperse channels are investigated. Models on pulse broadening are proposed, and the simulated results for a typical atmospheric condition and configurat

Pulses with a tunable central wavelength from 278-310 nm reaching <27 fs duration and >1 \mu J energy are generated by non-collinear four-wave mixing in a 0.5-mm...

We perform ultrafast transient absorption spectroscopy of oxy-hemoglobin by a pump-probe method with ultrashort laser pulses. Negative time-range of the observed traces, where the pump pulse precedes the probe pulse, is analyzed t