Abstract: In a method and apparatus for bonding a semiconductor laser chip to a heatsink and testing the bond obtained, temperature in the bonding operation is regulated by passing a small fixed current through the forward biased laser and monitoring corresponding change in voltage caused by alteration of the laser pn junction temperature. Current is passed to the laser through a floating contact consisting of a conducting vacuum pick-up pressed against the laser top surface. Bond integrity is subsequently tested at low temperature by passing a dc current greater than a threshold current through the laser and measuring the resulting light output and then passing a pulsed current with identical peak current level and again measuring light output. The difference in light output is a function of the bond thermal resistance.

Abstract: In a microwave apparatus for media which can be circulated and heated by high frequencies, an elongated shaft having a rectangular cross-section transverse to the elongated direction is provided at one end with a microwave transmitter. At the one end the shaft forms a hollow wave guide followed to the opposite end by a resonator chamber. The shaft has the same cross-sectional shape between its ends. A microwave permeable conductor in the form of a hairpin-shaped loop extends through the resonator chamber from the opposite end. The opposite end of the shaft is closed off by a flange plate secured to a flange on the shaft and the inlet and outlet ends of the loop are located in the flange plate.