At&t Bell Laboratories

American Telephone and Telegraph, Co.

At&t Technologies, Inc.

Norman R Dietrich

Yiu-Huen Wong

Ralph S Moyer

Anderson F Johnson, Jr

Walter R Holbrook

Palmer D Smeltz, Jr

Alfred Zacharias

An optical package for use with a laser diode in high speed applications. The package comprises a metallic housing with a multilayer ceramic (MLC) insert disposed through a sidewall thereof. The MLC insert is utilized to form a microstrip transmission line of a bandwidth sufficient to couple a high frequency signal source to the laser. A number of conductive vias are disposed through the thickness of the MLC insert at the package wall to serve as electric field shorts within the insert and improve the frequency response of the microstrip. A pair of such MLC inserts may be disposed through opposing sidewalls of the package and used to provide a conventional 'butterfly' configuration, while preserving the integrity of the microstrip interconnection.

High speed laser package

A silicon-based laser mounting structure is disclosed which provides improved interconnection between a semiconductor optical device, such as a laser, and an external high frequency modulation current source, by reducing the presence of parasitic inductive elements in the interconnecting network. The structure includes a stripline transmission path formed by depositing metal conductive strips on the top and bottom surfaces of a silicon substrate. The conductive strips are coupled at one end to the external modulation current source. A thin film resistor is deposited between the second end of the top conductive strip and the semiconductor optical device. This thin film resistor is utilized to provide impedance matching between the optical device and the stripline. That is, for a laser with an impedance Z.sub.L, and a stripline designed to have an impedance Z.sub.S, the resistance R is chosen such that R+Z.sub.L =Z.sub.S. Utilizing silicon processing techniques, the thin film resistor may be placed adjacent to the laser, reducing the parasitics associated with their interconnection. A conductive via is formed through the substrate to provide a top-side bonding location for connecting the optical device to the bottom metal conductor by providing the top-side site, the parasitic inductance associated with this interconnection is considerably reduced.

Method of forming a silicon-based semiconductor optical device mount

A silicon-based laser mounting structure is disclosed which provides improved interconnection between a semiconductor optical device, such as a laser, and an external high frequency modulation current source, by reducing the presence of parasitic inductive elements in the interconnecting network. The structure includes a stripline transmission path formed by depositing metal conductive strips on the top and bottom surfaces of a silicon substrate. The conductive strips are coupled at one end to the external modulation current source. A thin film resistor is deposited between the second end of the top conductive strip and the semiconductor optical device. This thin film resistor is utilized to provide impedance matching between the optical device and the stripline. That is, for a laser with an impedance Z.sub.L, and a stripline designed to have an impedance Z.sub.S, the resistance R is chosen such that R+Z.sub.L =Z.sub.S. Utilizing silicon processing techniques, the thin film resistor may be placed adajcent to the laser, reducing the parasitics associated with their interconnection. A conductive via is formed through the substrate to provide a top-side bonding location for connecting the optical device to the bottom metal conductor, by providing the top-side site, the parasitic inductance associated with this interconnection is considerably reduced.

Silicon-based mounting structure for semiconductor optical devices

A semiconductor laser mount is disclosed for use in high frequency (&gt;500 Mb/s) applications. The mount comprises a stripline transmission path and resistive element formed in series with the optical device. Since the current sources used to modulate optical devices at these bit rates have a large impedance relative to that of the optical devices, the stripline is used as an impedance controlling network to provide frequency independent coupling from the signal source to the device and the resistive element is used to compensate the variation of the impedance of the device to essentially match that of the stripline. Since the impedance of individual optical devices may vary, the resistive element is sized to provide optimum matching. Both the stripline and resistive element are integrated with the mount material to form a monolithic structure. Additionally, low frequency optical device inputs may be formed on an isolated portion of the mount to increase the versatility of the arrangement by increasing the operable bandwidth of the optical device.

Growing community of inventors

Allentown, PA, United States of America

Norman R Dietrich