Abstract: A test and burn-in socket for ball grid array type devices is disclosed. This socket is a true open top device in that there is no contact on the upper surface of the device under test. The test and burn-in socket further features dual contacts for simultaneous voltage and current measurements (Kelvin contacts). The socket additionally provides that the dual contacts serve as a latching mechanism to hold the device in place throughout the test and burn-in process.

Abstract: An optical coupling system having a high efficiency in coupling light from a light source to an optical fiber. The system may have a ball lens and an aspherical lens situated along the same optical path. The ball lens may be glass and the aspherical lens may be plastic. The ball lens may have optical aberrations common to spherical lenses. The aspherical lens may compensate for such aberrations. The glass ball lens may carry more power and have better thermal properties than the plastic lens, and thus compensate for latter's possibly weaker thermal properties. Together, the system may have sufficient power, low distortion, good thermal characteristics and high coupling efficiency.

Abstract: An optical coupling system having a split sleeve with a metallized strip adhered to a housing barrel at one end. The sleeve may be smaller than an optical fiber ferrule. The sleeve may have spring-like flexibility and be stretched open at the slit sufficiently to permit insertion of the ferrule in the sleeve. The sleeve may be made of zirconia. The ferrule may be held by the sleeve's spring-like contraction around the ferrule. Attached at the other end of the barrel may be an optoelectronic element such as a vertical cavity surface emitting laser. An optical fiber end of the ferrule may be aligned with the laser. Since the ferrule may be held firmly by the sleeve attached to the coupling barrel, there would be virtually no movement or wiggle of the fiber end relative to the laser and thus the alignment may be maintained.

Abstract: A coupler for coupling light between an optoelectronic element and an optical fiber. The coupler has a fiber stop that is made of a material that has an index of refraction that effectively matches the index of refraction of the optical fiber being coupled to the optoelectronic element. The fiber stop may be flat or rounded. It may be a discrete or molded part of the coupler assembly. The end of the fiber being stopped may be flat or rounded.