An apparatus for filtering an input beam of light to produce an output beam of light is provided. The hydrogen chloride-containing gas that is used preferably derives from a phosgenation or isocyanate forming reaction. Heat generated by lighting of LEDs of the lamp device is conducted from the cap portion to the fixture body and efficiently radiated. The forth rotation shaft is rotatably sleeved on the first rotation shaft and includes a forth bevel gear potion. The niobium monoxide gate may have a low work function suitable for use as an NMOS gate.