A methodology for treating the semiconductor laser as a current-controlled oscillator in an optical phase-lock loop is presented. The formalism is applied to phase demodulation of optical beams, reduction of phase noise by self-homodyning, and phase locking of a semiconductor laser array.

We established a new diode array pumped Er:Yb:Glass test setup for evaluation of the laser performance and q-switch characteristics of various saturable absorber materials at 1.54um. Pumping distribution and maximum gain was analyzed. Passive q-switched laser operation was demonstrated with both U: CaF2 and Co : MgAl2O4. TEMoo Qswitch pulses with energy of 0.5mJ and pulse width of 10ns was obta...

We have developed a high-speed confocal laser microscope. A microlens-array disk set in front of a pinhole-array disk improved optical efficiency more than ten times compared with that of conventional Nipkow confocal microscopy. This new microscope achieves a high-speed measurement of 1 frame/ms. We expect that it will be used for measuring biological and industrial active samples.

We demonstrate the generation of Bessel beams using an acousto-optic array based on a liquid filled cavity surrounded by a cylindrical multi-element ultrasound transducer array. Conversion of a Gaussian laser mode into a Bessel beam with tunable order and position is shown. Also higher-order Bessel beams up to the fourth order are successfully generated with experimental results very closely ma...

We demonstrate a novel application of a wavelength-swept fiber laser to fiber Bragg grating sensor-array interrogation. The laser provides high signal powers of >3 mW with <0.1-nm spectral resolution over a 28-nm wavelength span. Using time-interval counting, we demonstrate static-dynamic strain measurements with a resolution of 0.47mu? rms at a sampling rate of 250 Hz.

We report on the fabrication and operation of the first electrically pumped 1.55m vertical-cavity laser array for wavelength-division-multiplexing applications. The array consisted of four channels operating between 1509 and 1524 nm. Wafer bonding was used to integrate GaAs–AlGaAs distributed Bragg reflectors with an InP–InGaAsP active region.

Metal halide perovskites are promising materials for optoelectronic and photonic applications ranging from photovoltaics to laser devices. However, current perovskite devices constrained simple low-dimensional structures suffering limited design freedom holding up performance improvement functionality upgrades. Here, a micro-origami technique is developed program 3D microarchitectures toward ne...

Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG) changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output powe...

BACKGROUND The most common side effects of fractional laser skin treatment are erythema and edema. Low-level light therapy and light-emitting diode (LED) devices have been used to stimulate fibroblast activity and hasten wound healing. OBJECTIVE To determine whether LED treatment immediately after fractional laser skin resurfacing affects the severity and duration of postoperative eythema. ...

Terahertz (THz) radiation from a plasma filament array generated by focusing two-color laser pulses into the ambient air with microlens combining lens is investigated. We observed linear dependence of far-field collected THz on number filaments and separated bunches that are less than 1 mm in diameter. These results indicate individual contribute incoherently to entire output, which demonstrate...