Abstract: A thermistor assembly is formed by fixedly attaching a thermistor on to a base formed of a material having good heat conductivity and the thermistor assembly and an LD chip are fixedly attached on to a carrier arranged in contact with an electronic cooling element using brazing materials with different melting points, so that, when, for example, the thermistor is found faulty, the thermistor can be easily exchanged with a good one.

Abstract: A laser diode assembly capable of controlling a temperature of a laser diode chip with a high accuracy. A Peltier device is mounted on a base member, and a carrier is mounted on the Peltier device. On the carrier are mounted the laser diode chip, a thermistor, and a relay block. A terminal for connecting the thermistor to an external circuit is provided so as to extend through the base member. The thermistor and the relay block are connected together by wire bonding, and the relay block and the terminal are also connected together by wire bonding. The laser diode assembly further includes a control circuit for controlling a driving current for the Peltier device contacting with the carrier so as to maintain a resistance of the thermistor fixed on the carrier at a constant value.

Abstract: A rod lens fixing method which can prevent the generation of cracks in a rod lens due to annealing to be carried out after welding a lens assembly. The rod lens fixing method includes the steps of providing a flanged split sleeve having an axial slit extending continuously from one end of the flanged split sleeve to the other end thereof, the axial slit being wide enough at least a flange of the flanged split sleeve to permit laser welding; press-fitting the rod lens into the flanged split sleeve; and applying a solder into the axial slit to solder the rod lens to the flange split sleeve. This method further includes the steps of inserting the flanged split sleeve into a bore formed at one end portion of a sleeve, the bore having a diameter larger than an outer diameter of the flanged split sleeve and smaller than an outer diameter of the flange; and laser-welding the flange to one end surface of the sleeve at a plurality of points on an outer circumference of the flange and in the axial slit.