Abstract: A powdered surface monitoring system of additive manufacturing comprises an additive manufacturing processing cavity, having therein a working area carrying powder to be sintered; a laser source, generating a laser beam, which passes through a reflector, a dichroic mirror and a scanning vibration mirror and is transmitted to an upper surface of the powder in the working area; a polarization imaging device, having therein a beam expander group, a polarizer group and at least one photodetector, the polarizer group consisting of a plurality of linear polarizers, and the number of photodetectors being equal to the number of the linear polarizers.

Abstract: A powdered surface monitoring system of additive manufacturing comprises an additive manufacturing processing cavity, having therein a working area carrying powder to be sintered; a laser source, generating a laser beam, which passes through a reflector, a dichroic mirror and a scanning vibration mirror and is transmitted to an upper surface of the powder in the working area; a polarization imaging device, having therein a beam expander group, a polarizer group and at least one photodetector, the polarizer group consisting of a plurality of linear polarizers, and the number of photodetectors being equal to the number of the linear polarizers.

Abstract: An insert coaxial thermal radiation image evaluating system includes a cage support, first lens, first cage movable frame, second cage movable frame, cage holder and light detector. The first cage movable frame is movably disposed at the cage support and connected to the first lens. The second cage movable frame is movably disposed at the cage support and connected to the light detector. The cage holder is connected to the cage support to fix the cage support to an optical substrate. The first cage movable frame is movably disposed in the cage holder. The first lens and a second lens of a metal additive manufacturing system together form a structure of conjugate foci, such that a thermal radiation generated from a high-power infrared laser irradiation zone forms according to a fixed ratio an image captured by the light detector.

Abstract: An insert coaxial thermal radiation image evaluating system includes a cage support, first lens, first cage movable frame, second cage movable frame, cage holder and light detector. The first cage movable frame is movably disposed at the cage support and connected to the first lens. The second cage movable frame is movably disposed at the cage support and connected to the light detector. The cage holder is connected to the cage support to fix the cage support to an optical substrate. The first cage movable frame is movably disposed in the cage holder. The first lens and a second lens of a metal additive manufacturing system together form a structure of conjugate foci, such that a thermal radiation generated from a high-power infrared laser irradiation zone forms according to a fixed ratio an image captured by the light detector.

Abstract: A silicon based terahertz full wave liquid crystal phase shifter is provided. The liquid crystal phase shifter has a first silicon conductive substrate, a second silicon conductive substrate, a plurality of pads, and a liquid crystal. The first and second silicon conductive substrates, instead of the quartz glass and transparent electrode, such as ITO, are used as substrates and to provide electrodes of the liquid crystal phase shifter. Thus, the effect of the liquid crystal phase modulation of the liquid crystal phase shifter in the THz range can be improved.

Abstract: An apparatus for manufacturing a heat retaining multi-ply textile includes an adhesive tank; a lower drive roll partially submerged in the tank; an upper drive roll including spaced, longitudinal projections wherein the projections contact the lower drive roll to bring the adhesive onto the projections; two opposite driven rolls; a first supply spool for moving a continuous upper textile sheet wherein the continuous upper textile sheet moves to have its underside contacted the longitudinal projections when passing the upper drive roll before moves to a joining line of the driven rolls; a second supply spool for moving a continuous lower textile sheet to the joining line of the driven rolls wherein the continuous lower and upper textile sheets are pressed toward each other to form compartments; and an oven for heating in order to produce the production. Down migration can be avoided.

Abstract: The present invention coherent multiple-stage optical rectification terahertz wave generator discloses the generation of single-cycle terahertz radiation with two-stage optical rectification in GaSe crystals. By adjusting the time delay between the pump pulses employed to excite the two stages, the terahertz radiation from the second GaSe crystal can constructively superpose with the seeding terahertz field from the first stage. The high mutual coherence between the two terahertz radiation fields is ensured with the coherent optical rectification process and can be further used to synthesize a desired spectral profile of output coherent THz radiation. The technique is also useful for generating high amplitude single-cycle terahertz pulses, not limited by the pulse walk-off effect from group velocity mismatch in the nonlinear optical crystal used.

Abstract: The present invention discloses a means of the generation of tunable femtosecond pulses from 380 nm to 465 nm near the degenerate point of a 405-nm pumped type-I BBO non-collinearly phase-matched optical parametric amplifier (NOPA). The tunable UV/blue radiation is obtained from sum frequency generation (SFG) between the OPA output and the residual fundamental beam at 810-nm and cascaded second harmonic generation (SHG) of OPA. With a pumping energy of 75 mJ at 405 nm, the optical conversion efficiency from the pump to the tunable SFG is more than 5% and the efficiency of SHG of the OPA is about 2%.

Abstract: The present invention discloses a means of the generation of tunable femtosecond pulses from 380 nm to 465 nm near the degenerate point of a 405-nm pumped type-I BBO non-collinearly phase-matched optical parametric amplifier (NOPA). The tunable UV/blue radiation is obtained from sum frequency generation (SFG) between the OPA output and the residual fundamental beam at 810-nm and cascaded second harmonic generation (SHG) of OPA. With a pumping energy of 75 mJ at 405 nm, the optical conversion efficiency from the pump to the tunable SFG is more than 5% and the efficiency of SHG of the OPA is about 2%.