Design of a Low Loss and Large-Tolerance Optical Interface for Large-Area Optical Waveguides
circuit board using a step-out fabrication technique is proposed. In this paper, we simulated and compared our proposed structure to a typical straight core structure in order to investigate the misalignment tolerances and coupling excess losses.
Low-loss polymeric directional couplers and 8-inch large-area optical waveguides fabricated by laser-beam writing
Directional couplers and 8-inch large-area optical waveguides were successfully fabricated by a laser-beam writing technique. Their propagation losses were as low as those of waveguides patterned by a conventional photolithographic technique with a photomask.
Effects of reservoir volume on performance of pulse tube cooler.
A pulse tube cooler has the advantages of long-life and low-vibration over conventional cryocoolers such as G-M and Stirling coolers because of the absence of moving parts at low temperature. On the other hand, the combination of a reservoir and orifice is indispensable to optimize the performance of pulse tube coolers. In order to make the pulse tube cooler compact for practical applications, the volume of reservoir should be minimized. This paper analyzes the effects of the reservoir volume on the thermodynamic performance of various components in a simple orifice and a double-inlet pulse tube cooler by combining a linearized model with a thermodynamic analysis. Expressions of entropy production for those components are presented. The results show that the reservoir volume has a significant influence on the entropy production in the various components when the reservoir to pulse tube volume ratio is smaller than about 5. The ratio is important to determine the minimum reservoir volume for a pulse tube cooler. Optimum settings for a double-inlet pulse tube cooler are also discussed.