Abstract: A ballast water treatment device includes a filtration device and an irradiation device that irradiates, with ultraviolet rays, filtered water that has been filtered. The filtration device is a device that removes 99.999% or more of L-size organisms having a minimum part size of 50 ?m or more, and 90% or more of S-size organisms having a minimum part size of 10 ?m or more and less than 50 ?m. The irradiation device is capable of sterilizing the filtered water at a flow rate of 250 m3/h and a power consumption of 13 kW to eliminate 90% of S-size organisms immediately after a sterilization treatment.

Abstract: A pleated filter includes a filter base having folds that repeatedly form mountains and valleys and having a cylindrical shape whose axial direction is a ridge line direction of the folds. The pleated filter includes, in a valley projecting to the inside of the cylindrical shape, a bonded reinforcing portion extending in the ridge line direction of the folds.

Abstract: A pleated filter cartridge includes a pleated filter formed of a filter base having folds that repeatedly form peak portions and valley portions, the pleated filter having a shape of a cylinder whose axial direction is a ridge line direction of the folds, and lid portions disposed on an upper bottom and a lower bottom of the pleated filter. Reinforcing members whose top and bottom are fixed in the lid portions are provided in the valley portions viewed from the outside of the shape of the cylinder.

Abstract: A main portion 10 of an optical module 1 includes a thermoelectric cooler 21, and a chip carrier 22b placed on the cooler 21. A semiconductor light-emitting device 31, a lens 32, photodetectors 33a, 33b, and an etalon 34 are directly or indirectly mounted on the chip carrier 22b. Supporting members 36a and 36b are also fixed on the chip carrier 22b. A roof 35 is supported by the supporting members 36a, 36b and positioned above the etalon 34. The roof 35, supporting members 36a, 36b and chip carrier 22b are maintained at substantially equal temperatures by the cooler 21. As a result, the temperature of the etalon 34 is stabilized, and therefore the variation in the lock wavelength is suppressed.

Abstract: A main portion 10 of an optical module 1 includes a thermoelectric cooler 21, and a chip carrier 22b placed on the cooler 21. A semiconductor light-emitting device 31, a lens 32, photodetectors 33a, 33b, and an etalon 34 are directly or indirectly mounted on the chip carrier 22b. Supporting members 36a and 36b are also fixed on the chip carrier 22b. A roof 35 is supported by the supporting members 36a, 36b and positioned above the etalon 34. The roof 35, supporting members 36a, 36b and chip carrier 22b are maintained at substantially equal temperatures by the cooler 21. As a result, the temperature of the etalon 34 is stabilized, and therefore the variation in the lock wavelength is suppressed.

Abstract: A flat portion has a flat top surface, on which a chip carrier is provided. A light-emitting element is mounted on the chip carrier. A vertical portion is integral with the flat portion and extends vertically, i.e., perpendicularly to the flat top surface of the flat portion. A metal plate made of a metal having good welding performance is silver-brazed onto the vertical portion. A lens barrel containing a lens for focusing a light beam from the light-emitting element is inserted in a through-hole of the vertical portion and the metal plate, and welded to the metal plate so that the optical axes of the light-emitting element and the lens coincide with each other.