Abstract: It has been discovered that tilted optical fiber endfaces useful in low-reflection optical fiber joints can be produced by cleaving, provided the fiber is twisted through an appropriate twist angle. By way of example, for a particular, commercially available single mode fiber, the normalized twist angle typically is in the range of 5-15 degrees/cm, resulting in a nominal tilt angle of the fiber endface in the approximate range 5-20 degrees.

Abstract: Disclosed is an assembly for relatively high power light-emitting semiconductor devices that uses simple inexpensive components and construction to provide a heat coupler that reduces the thermal impedance between the active device and the ambient atmosphere by approximately a factor of ten from that of a comparable assembly not incorporating the inventive heat coupler. The active semiconductor device is directly mounted on the heat coupler. The coupler is fabricated from material having good thermal conductivity, such as copper, copper alloys, or aluminum, and is designed to have a large surface area, at least ten times the area of the bonding surface of the active device, in unobstructed contact with the ambient atmosphere, thereby providing efficient heat coupling between the heat source and the ultimate heat sink.