U.S. Philips Corporation

Hendrikus G Kock

Giok D Khoe

Hans-Jurgen Lydtin

Lambertus J Meuleman

Dieter Kuppers

Lodewijk J Van Ruyven

Johannes T Kluitmans

Hindrik Tjassens

Anthony H Deunhouwer

A laser diode module includes a rectangular box-shaped metal casing having a bottom (B), an even number of guide pins (1-14) being led through the bottom (B) in a standardized DIL order. In addition to the laser diode itself (LD) the laser diode module further includes a metal base carrier (BC) on which the laser diode (LD), a photo diode (PD) and a support (S) for the glass fiber (F) are installed. The laser diode module further includes a guide pin (9) which is inserted in the bottom (B) by means of a feedthrough insulator for electrically connecting the laser diode module to an external transmission line (MT). In order to achieve a proper matching of the laser diode module and the characteristic impedance of the external transmission line (MT), so that reflection phenomena are avoided and the laser diode module is made suitable for use in systems with considerably higher bit rates than 1 Gbit/s, the aforesaid guide pin (9) forms the inner guide of a coaxial transmission line situated inside the casing, of which transmission line the outer guide (CBL) is electrically conductively connected to the casing, whereas in the connecting line between the inner guide (9) and the laser diode (LD) a resistor (CS) is inserted having a value such that the sum of the resistances of this resistor (CS) and the laser diode (LD) is substantially equal to the characteristic impedance of the coaxial transmission line (9, CBL).

Laser diode module

An envelope for a photodiode which serves as a detector of light signals comprises a support and a metal cap-shaped member connected hermetically to the support. A metallized glass light conductor passed through an aperture of the cap-shaped member is connected in the aperture by means of solder. One end of the light conductor extends up to the photodiode; the other end projects from the cap-shaped member and is surrounded by the wall of an aperture on one side of a blocked-shaped member, in which aperture an optical fiber can be incorporated on the other side.

Envelope for a photodiode

Optical waveguide circuits, such as signal splitters, can be produced by etching grooves in a transparent, glass substrate and by filling the grooves with glass having a higher refractive index than the material of the substrate. The grooves have a semicircular cross-section and the filling glass is produced by a low temperature plasma-activated chemical vapor deposition process. Two substrates can be placed on top of each other, with the surfaces in which the filled grooves have been provided in contact, to form an integrated optical circuit.

Method of producing integrated optical waveguide circuits and circuits

For many optical communications systems, a semiconductor laser must be situated at an exact position and at an exact distance from a first optical element (for example a lens) of the optical system coupled to the laser. This is achieved according to the invention by arranging the laser in a bushing-shaped cover on which a flange is formed. A holder with a lens is secured on this flange by way of a plastic metal solder layer. The lens can be placed at the correct position and at the correct distance from the laser by sliding and by pressing on the holder. The solder layer is then plastically deformed while the space in which the laser is accommodated remains hermetically sealed.

Coupler comprising a light source and lens

A method of manufacturing cooling blocks for semiconductor lasers, in which the rounding-off radius of the line of intersection between two surfaces of the cooling blocks must have a very small value. In the method, two bodies to be formed into cooling blocks are each provided with a flat surface and these bodies are secured together with their flat surfaces by means of a curable adhesive. One side of the bodies connected together is subjected, transverse to the two surfaces connected together, to a machining treatment so as to obtain a further flat surface, in which machining treatment deformation and burring of the bodies near the line of intersection to be formed is avoided due to the presence of the cured adhesive, and a line of intersection having a rounding-off radius of only a few microns is formed.

Method of manufacturing cooling blocks for semiconductor lasers

In optical communication systems as well as in video disc playback equipment, it is necessary to position a light source such as a semiconductor laser at an exact distance from a lens of the optical system. In accordance with the invention this is done by mounting the laser in a tubular cover which is in a telescopic, press fit engagement with a holder provided with the lens. The desired exact distance between the laser and the lens is adjusted by relative compression between the cover and the holder. Because the engaging walls of the cover and holder are covered with a layer of indium, the walls will slide smoothly over each other during adjustment of the desired distance.

Optical coupler with a housing permitting adjustment of the distance

A microwave semiconductor device, for example, Gunn effect devices, avalanche diodes and varactors, having a mesa-like semiconductor body which is provided on both sides with respective grown metal contact layers. The upper side of the semiconductor body is provided with a beam lead which projects from the upper side. The metal contact layer of lower side of the semiconductor body is a grown heat sink or, as in the varactors, a beam lead.

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Eindhoven, Netherlands

Hendrikus G Kock