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An economical magnetocardiogram (MCG) system is built in our laboratory. It mainly consists of a MCG data acquisition stage equipped with two high-Tc superconducting quantum interference device (SQUID) magnetometers, a data processing stage with digital filtering and a one-layer μ-metal magnetically shielded room in conjunction with a high-Tc SQUID based active compensation. Experimental results show that a noise level of pico-tesla in MCG profiles, which is necessary for clinical applications, may be achieved with the system. Moreover, stable and convenient operations of the system are demonstrated with simulating MCG measurements.

An adaptive filter based on Data-Reusing Least-Mean-Square algorithm has been proposed and applied in magnetocardiography (MCG) to suppress ambient noise. Numerical simulation studies indicate that the adaptive filter is a powerful noise suppresser for correlated interferences, especially for those with amplitude changing and time delay. Also the filter has a wide frequency bandwidth. With this filter, the signal-to-noise ratio of an MCG is improved to the intrinsic noise level. The periodic average method for further improvement of the noise level in MCG is also discussed.

The fluorescent decays and spectra of pump power density dependent emission demonstrated that the excitation power density was enhanced in Rh640 dye solution containing scattering nanoparticles. Lasing in disordered scattering medium with low threshold, narrow bandwidth, and short duration was observed. The mechanism of this enhancement, together with the lasing properties of low threshold and narrow bandwidth, was discussed.

The interaction of the electrons with the phonons in GaAs/AlGaAs quantum wells, quantum well wires, and quantum well boxes has been studied by meansuring their time resolved photoluminescence (PL) spectra. In the quantum well (QW) system, relaxation time of the electron energy of the narrower well is shorter than that of the wider well. It is attributed to the stronger interaction of the electrons with the interface mode phonons. In the QW wires and QW boxes, the shortening of the relaxation time is obvious. It is due to the stronger electron-phonon interaction caused by the reduction of screening effect. Our experiments also demonstrated the incident laser intensity dependence of the relaxation time.

We propose and numerically simulate a nanoscale electro-optic (EO) switch based on a metal-insulator-metal structure composed of a strip waveguide and two side-coupled cavities filled with an EO material of 4-dimethyl-amino-N-methyl-4-stilbazolium tosylate, using the finite difference time domain method. It is found that the structure can be operated as an EO switch at a wavelength of 945 nm, with a modulation depth of 27 dB, a half-wave voltage of 5.3 V and a switching time of about 50 ps.

A high-resolution plasmonic refractive-index sensor based on a metal-insulator-metal structure consisting of a straight bus waveguide and a resonator waveguide is proposed and numerically simulated by using the finite difference time domain method under a perfectly matched layer absorbing boundary condition. Both analytic and simulated results show that the resonant wavelengths of the sensor have a linear relationship with the refractive index of material under sensing. Based on the relationship, the refractive index of the material can be obtained from the detection of one of the resonant wavelengths. The resolution of refractive index of the nanometeric plasmonic sensor can reach as high as 10−6, giving the wavelength resolution of 0.01 nm. It could be applied to highly-resolution biological sensing.

A full-duplex radio-over-fiber system using frequency-twelvefold optical millimeter-wave based on external modulation via a Mach–Zehnder modulator is proposed and analyzed theoretically. The simulation results show that the power penalties for both the downstream and upstream signals are less than 0.5 dB. In this scheme, the configuration of a base station is simplified without laser, while the frequency of local oscillator signal is largely reduced due to the frequency-twelvefold millimeter-wave technique. The cost of the new system is largely reduced.