GB2334142A

GB2334142A - Multiple function optical module

Info

Publication number: GB2334142A
Application number: GB9802338A
Authority: GB
Inventors: Jan Isaksson
Original assignee: Mitel Semiconductor AB
Current assignee: Microsemi Semiconductor AB
Priority date: 1998-02-04
Filing date: 1998-02-04
Publication date: 1999-08-11
Also published as: GB9802338D0

Abstract

A plurality of opto-electronic dies 10, comprising frames carrying respective opto-electronic devices having different functions, are assembled as a module on an optical source 24 in a stacked manner and aligned, e.g. by means of guides 26 and holes 22 in the frames. The devices may be emitters such as laser diodes or receivers, e.g. operating at different wavelengths, or a mixture of both. Passive elements such as mirrors 28 may also be included in the module. The configuration of the module can be easily changed.

Description

MULTIPLE FUNCTION OPTICAL MODULE The present invention relates to a method and apparatus for an optical module capable of multiple functions and more particularly, the present invention relates to a stacked arrangement of optoelectronic dies.

In the prior art, there have been attempts to maximize the functioning of optical components in order to increase the efficiency of the circuits in which they are integrated.

Typically, these efforts have lead to engineering, manufacturing or design complications, all of which contribute to cost increases and ineffective use of valuable research and development time.

It would be most desirable to have a method for the fabrication of a multiple functioning optical module which could be readily and expediitiously assembled and employed in a circuit. The present invention provides an optical module satisfying these requirements and a method of forming such a module. in accordance with one aspect of the present' invention, there is provided a multiple function optical module, comprising: a plurality of opto electronic die members, each member of the members having a frame for carrying an opto electronic device, each device for performing a function different from another device of the members; and an optical source having guide means; alignment means on the frame for aligning the die members on the guide means of the optical source, whereby the die members may be stacked on the guide means.

The module as detineated herein provides significant advantages over currently used arrangements in that the module may be customized for certain applications desired by the user. To this end, optical dies having completely different functions may be stacked one upon the other. Selection of the die will depend on the functions sought by the module designer.

Of particular convenience is the feature of passive alignment of the dies on the optical source. As is well known in the art, alignment is typically the most labour intensive aspect in the manufacture of optical components. By making use of framed optical die components together with a guide system associated with the optical source, as one possibility, the alignment procedure is greatly simplified while alignment precision remains uncompromised.

Duplex, coupler and multiple wavelength modules inter alia may be created using the technology set forth herein and thus, in a further aspect of the present invention, there is provided a method of forming a multiple function module, comprising: providing a plurality of opto electronic die members, each member of the members having a frame for carrying an opto electronic device, each device for performing a function different from another device of the members; an optical source having guide means; and alignment means on the frame for aligning the die members on the guide means of the optical source, whereby the die members may be stacked on the guide means to provide an optical module having a variety of functions.

As examples, modules may be formed to stack in alignment optoelectronic dies each for emitting a different wavelength. Further, the module may incorporate detector dies, each for detecting a different frequency.

For duplex operations, the module will include both transmitting and receiving dies in any number. Both passive and active components may be used and the modules integrated into a larger circuit.

Having thus generally described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments and in which; Figure 1 is a plan view of the lead frame for receiving an optical die; Figure 2 is a plan view of the lead frame for receiving an optical die according to a further embodiment; and Figure 3 is an exploded view illustrating the disposition of the dies on the optical source.

Similar numerals employed in the text denote similar elements.

Referring now to the drawings, Figure 1 illustrates a first example of the optical die, generally denoted by numeral 10, for use in the present invention. A laser diode 12 is provided and a carrier or lead frame 14 is connected to the substrate and to laser diode 12 via contact pads 16 and 18. This configuration permits fliFchip bonding of laser diode to the pads while permitting the surface emitting laser to provide a collimated beam in a direction away from the plane of the contacts. As is known, the end strip 20 is removed after the laser has been attached and the package otherwise completed in order to isolate the two pads 16 and 18.

Lead frame 14 also has apertures 22 which are precisely aligned in relation to the bonding pads 1618. The apertures 22 facilitate passive alignment with guides on the optical source discussed herein after.

Figure 2 illustrates a further optical die induding a diode array 12'. It will be understood that the dies shown are only examples and optoelectronic component choice will depend on the requirements of the user.

Figure 3 is an exploded view of a stacked module. The optical source 24 may be any suitable source, of which there is an abundance in the prior art, useful with dies and accordingly detailed description will be obviated. The source 24 will include guides 26 shown in the example as projections, which may be machined or otherwise attached to source 24 as shown.

Guides 26 receive dies 10 at apertures 22 to ensure precise alignment between the optical device, in the example diodes 14, and optical fibers, broadly denoted by numeral 28.

The dies each may perform discreet functions as discussed supra to thus provide a multiple function module allowing the designerto select which functions are useful in a given situation.

As an altemative, the module shown in Figure 3 may optionally include passive elements 28 such as optical mirrors. In this arrangement, the active elements ( optical devices connected to the dies 10 ) may alternate with passive elements 28. Further, a series of elements 28 may be interposed with dies 10. Other combinations of elements are also possible. The module of Figure 3 may also be incorporated into an integrated circuit (not shown ) or mounted to circuit board (not shown).

Although specific embodiments of the invention have been discussed it will be appreciated that the invention is subject to substantial variation without departing from the spirit, nature or scope of the described and claimed invention.

Claims

LAIMS:

1. A multiple function optical module, comprising: a plurality of opto electronic die members, each member of said members having a frame for carrying an opto electronic device, each said device for performing a function different from another device of said members; an optical source having guide means; and alignment means on said frame for aligning said die members on said guide means of said optical source, whereby said die members may be stacked on said guide means.

2. The optical module as defined in daim 1, wherein said optoelectronic die members include active optical components and passive optical components.

3. The optical module as defined in claims 1 and 2, wherein said module indudes an opto electronic die receiving member for receiving a wavelength and a transmitting member for transmitting a wavelength.

4. The optical module as defined in claims I through 3, wherein said receiving member and said transmitting member are in alternating relation.

5. The optical module as defined in daim 4, wherein said receiving member comprises a single receiver and said transmitter comprises a single transmitter.

6. The optical module as defined in claims 4 and 5, wherein said receiving member comprises an array receiver and said transmitter comprises an array transmitter.

7. The optical module as defined in claims 1 through 6, wherein said module comprises an optical coupler.

8. The optical module as defined in claims 1 through 7, wherein each said opto electronic die member includes at least one of a flip chip bonded vertical cavity surface emitting diode, detector diode or micro cavity diode.

The optical module as defined in claim 2, wherein said passive optical components include dichroic mirrors.

10. The optical module as defined in claim 1, wherein said alignment means comprises apertures in said die members.

11. The optical module as defined in claim 1, wherein said die members are passively aligned.

12. A method of forming a multiple function module, comprising providing a plurality of opto electronic die members, each member of said members having a frame for carrying an opto electronic device, each said device for performing a function different from another device of said members; an optical source having guide means; and alignment means on said frame for aligning said die members on said guide means of said optical source, whereby said die members may be stacked on said guide means to provide an optical module having a variety of functions.

13. The method as defined in claim 12, further including the step of simultaneously transmitting and detecting wavelengths with said module.

14. The method as defined in claims 12 or 13, further including the step of simultaneously detecting a plurality of wavelengths of different frequency.

15. The method as defined in daims 12 through 14, further including the step of mounting said module to an electronic circuit board.