CA1108900A - Electro-optic device housing for fiber-optic applications - Google Patents
Electro-optic device housing for fiber-optic applicationsInfo
- Publication number
- CA1108900A CA1108900A CA311,434A CA311434A CA1108900A CA 1108900 A CA1108900 A CA 1108900A CA 311434 A CA311434 A CA 311434A CA 1108900 A CA1108900 A CA 1108900A
- Authority
- CA
- Canada
- Prior art keywords
- electro
- optic device
- device housing
- sidewall
- housing according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4202—Packages, e.g. shape, construction, internal or external details for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
- G02B6/421—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms the intermediate optical component consisting of a short length of fibre, e.g. fibre stub
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4248—Feed-through connections for the hermetical passage of fibres through a package wall
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
- G02B6/4401—Optical cables
- G02B6/4415—Cables for special applications
- G02B6/4427—Pressure resistant cables, e.g. undersea cables
- G02B6/4428—Penetrator systems in pressure-resistant devices
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Couplings Of Light Guides (AREA)
Abstract
ELECTO-OPTIC DEVICE HOUSING FOR FIBER-OPTIC APPLICATIONS
ABSTRACT OF THE DISCLOSURE
An electro-optic device housing for fiber-optic applications comprising a header, an electro-optic device bonded to said header, electrodes inserted through said header, means for electrically connecting said device to said electrodes, a sidewall bonded to said header, an optical fiber guide tube inserted in an opening in said sidewall, bonded to said sidewall and extending radially outward from the inner surface of said sidewall, an optical fiber inserted in said fiber guide tube and extending from outside said sidewall through said sidewall toward said electro-optic device, and a cover plate bonded to said sidewall which completes the enclosure of said electro-optic device, said electrodes and that portion of the optical fiber interior to said sidewall.
ABSTRACT OF THE DISCLOSURE
An electro-optic device housing for fiber-optic applications comprising a header, an electro-optic device bonded to said header, electrodes inserted through said header, means for electrically connecting said device to said electrodes, a sidewall bonded to said header, an optical fiber guide tube inserted in an opening in said sidewall, bonded to said sidewall and extending radially outward from the inner surface of said sidewall, an optical fiber inserted in said fiber guide tube and extending from outside said sidewall through said sidewall toward said electro-optic device, and a cover plate bonded to said sidewall which completes the enclosure of said electro-optic device, said electrodes and that portion of the optical fiber interior to said sidewall.
Description
ELECTRo-OPTIC DEVICE HOUSING FOR FIBER-OPTIC APPLICATIONS
This invention relates to a novel electro-optic device housing useful in fiber optic communication systems.
BACKGROUND OF THE I~NTION
Commun~c~tion systems using ~odulated light waves transmitted through opt~cal ~i~ers are ~ecoming o~
increasing commercial importance~ In these systems, t~e moduiated output o~ a light source is coupled into an optical ~ber, transmitted through the optical ~er to another location and detected by a l~ght de~ec~or w~ich converts the incident modulated light sign~l to a modulated electrical signal corresponding to the orig~nal electr~cal 16 signal impressed upon the light source These systems o~fex the advantages o~ large signal ~and~idth, i~munity from electrical noise, and small size. To ~e rel~a~le~
the components of ~uch systems must be shielded against the severe environment~l conditions o~ten found ~n transmission and rece~ing inst~llations and in t~e`
distances ~etween 5uc~ installations~
The light source used in such systems ~s typicall~ a semiconductor pn ~unction light em~tting diode or in~ect~on l~ser. The light detectox used ~.n such 26 system~ is t~p~c~lly ~ p-i-n or ~valanche photodiode~
The device ~ousing includes ~ he~der on w~ich the electro~optic device suc~ as ~ light source or detector is mounted. ~Electx~des, required ~or supply~n~
power to the electxo-optic device ~nd transmitting ~ elQctrical signals to or ~rom the dev~cer ~re ~nserted through the header, The open~n~s in the hQ~der t~rough wh~ch the electrodes ~re inserted ~re sealed us~ng ~
glass to met~lt epox~ res~n or solder se~ elect~c~l : cont~ct to t~e neader is des~.red, to ~orm a ~ermetic .:
36 se~l het~een the electrode ~nd t~e header. T~e cap w~th a l~r~e ~re~ windo~ in ~.t, suc~ ~s th~t sh~wn ~n U, S, P~tent 3,8a5,347 ~s~ued ~pr~l 23, 1974~ to Coll~ns et al~
~nd U. S. Patent 3,946,416 ~ssued March.23~ 1~76~ ko - H~cskaylo, to permit tr~nsmiss-~on o~ t in~o o~ out o~ the housing, is ~oldered ox ~e1ded to the cap to ~orm ' - :
.
- : . : ~ .
. .': . , : ' ~ . '' :
. ~ .
~ ~ . .. . . : -:
a hermetic seal therebetween.
~ Light sources or detectors mounted in such prior art housings are not suitable for use in a fiber optic communication system since the window of the package will be typically at least 0.1 cm in thickness, and the source or detector will be mounted some distance behind the ~nside surface o~ the windo~, typically ~ 05 cm or more. Since light emitted by a semiconductor light emitting diode or injection laser diverges with a large angle, an optical fiber must be close to the emit~ing surface to efficiently couple the light output into the optical fiber.
Correspondingly, light emitted rom the end of the optical fiber diverges with a large angle, so that the optical 1~ fiber must be close to the light detector in order to ob-tain the maximum elec-crical output from the detectox.
Another problem with housings for electro-optic devices is the assembly of the electro-optic device and housing. The alignment of the optical fiber with the electro-optic device must be accurate in order to obtain maxim~n coupling in or out of the optical fiber and must be maintained during subsequent assembly operations. There can be no movement of the optical fiber during the final assembly operations since slight misalignment leads to a product with reduced efficiency.
Operations of fiber optlc communication systems at wavelengths of about 1 miGron to about 1.2 microns are o~ interest because of the low dispersion of the commercial-ly available optical fibers in this wavelength region.
~30 However, in this wavelength region, thè sensitivity of silicon light detectors is low because of the low absorption constant of silicon. Therefore, a long path length in the detector is required in order to maintain maximum electrical output signals. One method of obtain ing such a long pa'ch length is to couple lighk into the detector parallel to the plane of the p-n junction of the detsctor such that it propagates parallel to and in the plane of the junction.
A further reason for having a device housing in 4~ which the optical fiber enters through the side of the ' , housing is that the light sources and detectors in such housings are o~ten mounted on electrical circuit boards which are stacked close together, with the space allowed for such housings of about 3/8 of an inch between the circuit boards. It is there~ore de~irable to have the fiber exit from the light source or detector in a direction at right angles to the electrodes and there~ore parallel to the circuit boards.
Therefore, it is desirable to have an electro-optic device housing in which a fiber can be mounted and aligned in close proximity to an electro-optic device, which provides a long path leng~h ~or absorp~ion o~ light in the wavelength region between 1.0 and 1.2 microns and 1~ which has ease and rellability o~ assembly.
Goell et al, U. S. Patent 4,065,203 issued December 27, 1977, teach the use o~ an opt;cal fiber con-tained in a support tube whioh is inserted through an openin~ in a cap for a laser diode housing. The support tube is glued both to the mount o~ the laser diode and to the cap o~ the laser diode housing extending ~hrough this housing to the règion outside the cap. ~Goell et al teach that the cap must ~e mounted on the header a~ter the alignment of the ~iber and the electro-optic device
This invention relates to a novel electro-optic device housing useful in fiber optic communication systems.
BACKGROUND OF THE I~NTION
Commun~c~tion systems using ~odulated light waves transmitted through opt~cal ~i~ers are ~ecoming o~
increasing commercial importance~ In these systems, t~e moduiated output o~ a light source is coupled into an optical ~ber, transmitted through the optical ~er to another location and detected by a l~ght de~ec~or w~ich converts the incident modulated light sign~l to a modulated electrical signal corresponding to the orig~nal electr~cal 16 signal impressed upon the light source These systems o~fex the advantages o~ large signal ~and~idth, i~munity from electrical noise, and small size. To ~e rel~a~le~
the components of ~uch systems must be shielded against the severe environment~l conditions o~ten found ~n transmission and rece~ing inst~llations and in t~e`
distances ~etween 5uc~ installations~
The light source used in such systems ~s typicall~ a semiconductor pn ~unction light em~tting diode or in~ect~on l~ser. The light detectox used ~.n such 26 system~ is t~p~c~lly ~ p-i-n or ~valanche photodiode~
The device ~ousing includes ~ he~der on w~ich the electro~optic device suc~ as ~ light source or detector is mounted. ~Electx~des, required ~or supply~n~
power to the electxo-optic device ~nd transmitting ~ elQctrical signals to or ~rom the dev~cer ~re ~nserted through the header, The open~n~s in the hQ~der t~rough wh~ch the electrodes ~re inserted ~re sealed us~ng ~
glass to met~lt epox~ res~n or solder se~ elect~c~l : cont~ct to t~e neader is des~.red, to ~orm a ~ermetic .:
36 se~l het~een the electrode ~nd t~e header. T~e cap w~th a l~r~e ~re~ windo~ in ~.t, suc~ ~s th~t sh~wn ~n U, S, P~tent 3,8a5,347 ~s~ued ~pr~l 23, 1974~ to Coll~ns et al~
~nd U. S. Patent 3,946,416 ~ssued March.23~ 1~76~ ko - H~cskaylo, to permit tr~nsmiss-~on o~ t in~o o~ out o~ the housing, is ~oldered ox ~e1ded to the cap to ~orm ' - :
.
- : . : ~ .
. .': . , : ' ~ . '' :
. ~ .
~ ~ . .. . . : -:
a hermetic seal therebetween.
~ Light sources or detectors mounted in such prior art housings are not suitable for use in a fiber optic communication system since the window of the package will be typically at least 0.1 cm in thickness, and the source or detector will be mounted some distance behind the ~nside surface o~ the windo~, typically ~ 05 cm or more. Since light emitted by a semiconductor light emitting diode or injection laser diverges with a large angle, an optical fiber must be close to the emit~ing surface to efficiently couple the light output into the optical fiber.
Correspondingly, light emitted rom the end of the optical fiber diverges with a large angle, so that the optical 1~ fiber must be close to the light detector in order to ob-tain the maximum elec-crical output from the detectox.
Another problem with housings for electro-optic devices is the assembly of the electro-optic device and housing. The alignment of the optical fiber with the electro-optic device must be accurate in order to obtain maxim~n coupling in or out of the optical fiber and must be maintained during subsequent assembly operations. There can be no movement of the optical fiber during the final assembly operations since slight misalignment leads to a product with reduced efficiency.
Operations of fiber optlc communication systems at wavelengths of about 1 miGron to about 1.2 microns are o~ interest because of the low dispersion of the commercial-ly available optical fibers in this wavelength region.
~30 However, in this wavelength region, thè sensitivity of silicon light detectors is low because of the low absorption constant of silicon. Therefore, a long path length in the detector is required in order to maintain maximum electrical output signals. One method of obtain ing such a long pa'ch length is to couple lighk into the detector parallel to the plane of the p-n junction of the detsctor such that it propagates parallel to and in the plane of the junction.
A further reason for having a device housing in 4~ which the optical fiber enters through the side of the ' , housing is that the light sources and detectors in such housings are o~ten mounted on electrical circuit boards which are stacked close together, with the space allowed for such housings of about 3/8 of an inch between the circuit boards. It is there~ore de~irable to have the fiber exit from the light source or detector in a direction at right angles to the electrodes and there~ore parallel to the circuit boards.
Therefore, it is desirable to have an electro-optic device housing in which a fiber can be mounted and aligned in close proximity to an electro-optic device, which provides a long path leng~h ~or absorp~ion o~ light in the wavelength region between 1.0 and 1.2 microns and 1~ which has ease and rellability o~ assembly.
Goell et al, U. S. Patent 4,065,203 issued December 27, 1977, teach the use o~ an opt;cal fiber con-tained in a support tube whioh is inserted through an openin~ in a cap for a laser diode housing. The support tube is glued both to the mount o~ the laser diode and to the cap o~ the laser diode housing extending ~hrough this housing to the règion outside the cap. ~Goell et al teach that the cap must ~e mounted on the header a~ter the alignment of the ~iber and the electro-optic device
2~ thus providing an opportunity for a disturbance of the alignment of the electro-optic device and the optical fiber.
SUMMAR~ OF THE INVENTION
An electro-optic device housiny for fiber optic applications compri~es a header, an electro-optic device bonded to said header, electrodes inserted through said header, means for electrically connecting said device to said electrodes, a sidewall bonded to said header, an optical fiber guide tube inserted in an opening in said ~5 sidewall, bonded to said sidewall and extending radially outward ~rom the inner surface of said sidewall, an optical fiber inserted in said fiber guide tube and - extending from out~ide said sidewall hrouyh said sidewall towards said electro-optic device, and a cover pla~e bond-ed to said sidewall which completes the enclosure of said .
electro-optic devica, said electrodes and that port.ion of the optical fi~er interior to said sidewall.
BRIEF DE5CRIPTION OF T~E INVENTION
6 FIG. 1 shows a top view of the electro-optic device housing of the invention.
FIG. 2 shows a cross-secti.onal view along line 2-2 of the electro-optic device housing shown in FIG. 1.
FIG. 3 shows another cross sectional view along line 3-3 of the electro-optic device housing shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVEN~ION
The invention is a three-part, side-sntry, electro-optic device housing including a header, side--1~ walls and cap. In the FIGURES, the electro-optic device housing 10 of the invention includes a header 12 through which are inserted electrodes 14 and 16 which are hermetically sealed to the header 12 by sealing means 18. . .
The sealing means 18 includes glass to metal seals, cured epoxy resins or, i electrical contact o one of the electrodes to the housing is desired, soldering or welding~
Bonded to the header 12 is a mounting block 20 whose upper sur~ace 21 is meta~lized. An electro-optic device 22 is bonded to the upper surface 21 of the mounting blcck 20 2~ by soldering or other means. Alternatively, the mounting block can be removed and the electro-optiG device 22 bonded directly to the header 12. Wires 24 and 26 make the electrical contact between the electrodes 14 and 16 and the electro-optic device 22.
~ ~he electro-optic device 22 can be a light source such as a semiconductor pn junction light emitting diode or an injection laser such as an AlGaAs double hetero-~unctlon continuous wave injection laser. Altexnatively, the electro-optic device can be a light detector. Suit-~5 able light detectors include photoconductors, depletion layer devices such as p-i-n photodiodes, or avalanche photodiodes. Alternatively, both a light source and ~ .
detector can be combined in the same device or mounted ` separately within the device housing 10. In a~dition, an - : , .. .
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electrical device which can comprise an electrical circuit or circuits coupled to the electro-optic device 22, and ~ to one or more electrodes including elec~rodes 14 and 16, can be mounted within the electro-optic device housing 10.
5uch electrical devices can include an electro-optic device temperature compensation circuit and sensors, a light source dr~ver amplifier, a feedback circuit for maintaining constant light output from a light source, a light detector preamplifier and the like.
A sidewall 28,which can be a ring or other geometric configuration, is bonded to the header at the joint 30. An opening 32 is formed in the sidewall 28.
A fiber guide tube 34 is inserted into t.he opening 32 and 16 bonded to the sidewall 28. The iber guide tube 34 ax-tends from outside the sidewall 28 to about the inner surface of the sidewall 28. A fiber optic cable 36 which contains an optical fiber 38 is inserted into the fiber guide tube 34. The optical fiber 38 extends inside the sidewall 28 towards the electro-optic device 22. A
strain relief member 40, such as heat shrinkable tubing, is fitted over the fiber guide tube 34 and the fiber optic cable 36 and extends a distance outward alony the fiber optic cable 36. The optical fiber 38 is hermetically ~6 sealed to the sidewall 28 using sealing means 42. A
support block 44 can be mounted on the mounting block 20 to support the optical fiber 38 when it is aligned with the light emitting or light sensitive surface of the electro-optic device 22. Alternatively, the optical ~0 iber 38 can be supported by the mounting block 20~
A cap ~6 is bonded to the sidewall 28 at the joint 48 to form a hermetic seal therebetween.
Thè fiber optic cable 36 containing the light transmitting fiber 38 extends outward from the ring 28 forming a fiber pigtail. This fiber pigtail can be terminated by a connector 50 suitable for interconnection of the optical fiber of the pigtail with another fiber optic cable containing an optical Fiber.
The optical fiber 38 transmits light emitted by an electro-optic device out of the housing. Suitable . . , , ' ' -light emitting devices include a semiconductor pn junction light èmit~ing'diode or a semiconductor pn junction laser, or any other ~odulatable light source. Altexnatively, light emitted by an external source of light, such as an optical fiber contained in a fiber optic cable, into the optical fiber of the pigtail is transmitted into the housing and detected by an electro-optic device such as a light detector.
The utility of the electro-optic device housing of the invention, a three part, side entry housing, is that the position sensitive components, the electro-optic device and the optical fiber, can be accurately aligned and tied down before the assembly is completed.
1~ In the assembly of this housing two parts, the header and sidewall, as well as the electro-optic device and the optical fiber, are assembled and the optical fiber and the electro-optic device are aligned with one another before the third part of the housing, the cap, is joined to the remainder o the housing. ~ince the cap does not contact either the optical fiber or the electro-optic de~ice, it cannot disturb the alignment of these compo-nents.
Using the housing of the in~ention, a light 2~ detector with a high sensitivity to light with a wave-length of 1.06 microns can be ~abricated. ~he light dete~tor and optical fiber are aligned such that li~ht emitted from the optical fiber towards the detector propagates parallel to and in the p-n junction plane, ~hus resulting in a long a~50rbi~ length in the detector.
The approach is easible since the accurate alignment o the optical fiber and the light deteator is not ~is-~urbed during subsequent assembly steps~
Such a housing was assembled as ~ollows.
~6 A ring, with a guide tube inserted into an opening in the ring and bonded to the ring, was welded to a header using standard resistance wel~ing techniques.
A ceramic mounting block was soldered to ~he header~ An optical fiber with a 100 micron diameter core, a 200 micron outside diameter and a numerical aperture o~ 0.25 was in-.. . , . :: ' - ;, ~ ,- ', ': , ' .. ' ,. .
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-~ - ... - - .. . .: , :, . :- . : ... .:
-: ... - :. . . . .
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serted through the guide tube and rested on a mounting block~b~nded tQ the header. The optical fiber was bonded to the inner diameter of the ring using a curable epoxy 6 resin thus forming a hermetic seal therebetween. The optical fiber was not bonded to the mounting block but it is preferred to bond the optical iber to the mounting block using bonding means such as a curable epoxy resin.
The design of the p-i-n photodiode to be mounted in the housing was optimized for 1.06 microns. The thickness of the diode was 150 microns. The fan out of light emitted from the optical fiber i5 accommodated by the increasiny width of the sansitive region of the photo-diode. The sensitive length of the diode was 2 mm and 16 the light traversed about 0.24 mm of an insensitive region beore reaching the sensitive region of the photodiode.
The p-i-n photodiode, with its electrodes attàched to an e~ternal bias voltage supply and signal detection circuits was then aligned with the light beam emitted from the optical fiber such that the maximum `~ electrical output signal was obtained from the photodiode.
A molybdenum tab was`used as a ~him be~ween the photodiode and the mounting block to obtain'the correct height for the detector. The photodiode was then bonded to the mount-~
ing block using an electrically conducting cuxable epoxyresin. ~he position of the photodiode was such that the light beam was propagated parallel to and in the pn ~unction plane o the photodiode.
The cap was then welded to the ring usin~
standard xesistance welding techniques.
' To obtain a measure of the improvement in detectox quantum e~iciency, the 1~06 micron wavelength light from a tungsten filament lamp tranæmitted through a narro~ band filter was first ~ocussed on a calibra~ed 86 photodiode, impinging on the calibrated photodiode normal to the pla~ne of the p-n junction. The calibrated photodiode was known to have a quantum efficiency of 24%
at 1.06~microns~ The light was then ocussed onto the end of the optical fiber external to the housing. ~he quantum efficiency of the optical fiber plus photodiode mounted : ' ':
' ' ' , ' in the housing was 36%. If the antireflection coating at 1.06 microns~is applied to the edge of the photodiode it is estimated that the quantum efficiency would increase 6 to ~bout 50~. If in addition an antireflection coating is applied to the ends of the optical fiber, ~hen it is estimated that the quantum efficiency for the device in the housing would increase to about 52%~
To show the effect of antireflection coatings, a drop of a light-transmitting curable epoxy resin was placed between and touching both the end of the optical fiber internal to the housing and the edge of the phato-diode. The measured quantum efficiency increased to about 45% from 36%.
1~ ;
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.
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~ ' ., ' . , .
SUMMAR~ OF THE INVENTION
An electro-optic device housiny for fiber optic applications compri~es a header, an electro-optic device bonded to said header, electrodes inserted through said header, means for electrically connecting said device to said electrodes, a sidewall bonded to said header, an optical fiber guide tube inserted in an opening in said ~5 sidewall, bonded to said sidewall and extending radially outward ~rom the inner surface of said sidewall, an optical fiber inserted in said fiber guide tube and - extending from out~ide said sidewall hrouyh said sidewall towards said electro-optic device, and a cover pla~e bond-ed to said sidewall which completes the enclosure of said .
electro-optic devica, said electrodes and that port.ion of the optical fi~er interior to said sidewall.
BRIEF DE5CRIPTION OF T~E INVENTION
6 FIG. 1 shows a top view of the electro-optic device housing of the invention.
FIG. 2 shows a cross-secti.onal view along line 2-2 of the electro-optic device housing shown in FIG. 1.
FIG. 3 shows another cross sectional view along line 3-3 of the electro-optic device housing shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVEN~ION
The invention is a three-part, side-sntry, electro-optic device housing including a header, side--1~ walls and cap. In the FIGURES, the electro-optic device housing 10 of the invention includes a header 12 through which are inserted electrodes 14 and 16 which are hermetically sealed to the header 12 by sealing means 18. . .
The sealing means 18 includes glass to metal seals, cured epoxy resins or, i electrical contact o one of the electrodes to the housing is desired, soldering or welding~
Bonded to the header 12 is a mounting block 20 whose upper sur~ace 21 is meta~lized. An electro-optic device 22 is bonded to the upper surface 21 of the mounting blcck 20 2~ by soldering or other means. Alternatively, the mounting block can be removed and the electro-optiG device 22 bonded directly to the header 12. Wires 24 and 26 make the electrical contact between the electrodes 14 and 16 and the electro-optic device 22.
~ ~he electro-optic device 22 can be a light source such as a semiconductor pn junction light emitting diode or an injection laser such as an AlGaAs double hetero-~unctlon continuous wave injection laser. Altexnatively, the electro-optic device can be a light detector. Suit-~5 able light detectors include photoconductors, depletion layer devices such as p-i-n photodiodes, or avalanche photodiodes. Alternatively, both a light source and ~ .
detector can be combined in the same device or mounted ` separately within the device housing 10. In a~dition, an - : , .. .
'- ' . . .:; . ' :
, : : : -- - .:: . : .
. . . . . . . . .
:
~38~
electrical device which can comprise an electrical circuit or circuits coupled to the electro-optic device 22, and ~ to one or more electrodes including elec~rodes 14 and 16, can be mounted within the electro-optic device housing 10.
5uch electrical devices can include an electro-optic device temperature compensation circuit and sensors, a light source dr~ver amplifier, a feedback circuit for maintaining constant light output from a light source, a light detector preamplifier and the like.
A sidewall 28,which can be a ring or other geometric configuration, is bonded to the header at the joint 30. An opening 32 is formed in the sidewall 28.
A fiber guide tube 34 is inserted into t.he opening 32 and 16 bonded to the sidewall 28. The iber guide tube 34 ax-tends from outside the sidewall 28 to about the inner surface of the sidewall 28. A fiber optic cable 36 which contains an optical fiber 38 is inserted into the fiber guide tube 34. The optical fiber 38 extends inside the sidewall 28 towards the electro-optic device 22. A
strain relief member 40, such as heat shrinkable tubing, is fitted over the fiber guide tube 34 and the fiber optic cable 36 and extends a distance outward alony the fiber optic cable 36. The optical fiber 38 is hermetically ~6 sealed to the sidewall 28 using sealing means 42. A
support block 44 can be mounted on the mounting block 20 to support the optical fiber 38 when it is aligned with the light emitting or light sensitive surface of the electro-optic device 22. Alternatively, the optical ~0 iber 38 can be supported by the mounting block 20~
A cap ~6 is bonded to the sidewall 28 at the joint 48 to form a hermetic seal therebetween.
Thè fiber optic cable 36 containing the light transmitting fiber 38 extends outward from the ring 28 forming a fiber pigtail. This fiber pigtail can be terminated by a connector 50 suitable for interconnection of the optical fiber of the pigtail with another fiber optic cable containing an optical Fiber.
The optical fiber 38 transmits light emitted by an electro-optic device out of the housing. Suitable . . , , ' ' -light emitting devices include a semiconductor pn junction light èmit~ing'diode or a semiconductor pn junction laser, or any other ~odulatable light source. Altexnatively, light emitted by an external source of light, such as an optical fiber contained in a fiber optic cable, into the optical fiber of the pigtail is transmitted into the housing and detected by an electro-optic device such as a light detector.
The utility of the electro-optic device housing of the invention, a three part, side entry housing, is that the position sensitive components, the electro-optic device and the optical fiber, can be accurately aligned and tied down before the assembly is completed.
1~ In the assembly of this housing two parts, the header and sidewall, as well as the electro-optic device and the optical fiber, are assembled and the optical fiber and the electro-optic device are aligned with one another before the third part of the housing, the cap, is joined to the remainder o the housing. ~ince the cap does not contact either the optical fiber or the electro-optic de~ice, it cannot disturb the alignment of these compo-nents.
Using the housing of the in~ention, a light 2~ detector with a high sensitivity to light with a wave-length of 1.06 microns can be ~abricated. ~he light dete~tor and optical fiber are aligned such that li~ht emitted from the optical fiber towards the detector propagates parallel to and in the p-n junction plane, ~hus resulting in a long a~50rbi~ length in the detector.
The approach is easible since the accurate alignment o the optical fiber and the light deteator is not ~is-~urbed during subsequent assembly steps~
Such a housing was assembled as ~ollows.
~6 A ring, with a guide tube inserted into an opening in the ring and bonded to the ring, was welded to a header using standard resistance wel~ing techniques.
A ceramic mounting block was soldered to ~he header~ An optical fiber with a 100 micron diameter core, a 200 micron outside diameter and a numerical aperture o~ 0.25 was in-.. . , . :: ' - ;, ~ ,- ', ': , ' .. ' ,. .
. - ~ : : . . -: : , . . . . .
-~ - ... - - .. . .: , :, . :- . : ... .:
-: ... - :. . . . .
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serted through the guide tube and rested on a mounting block~b~nded tQ the header. The optical fiber was bonded to the inner diameter of the ring using a curable epoxy 6 resin thus forming a hermetic seal therebetween. The optical fiber was not bonded to the mounting block but it is preferred to bond the optical iber to the mounting block using bonding means such as a curable epoxy resin.
The design of the p-i-n photodiode to be mounted in the housing was optimized for 1.06 microns. The thickness of the diode was 150 microns. The fan out of light emitted from the optical fiber i5 accommodated by the increasiny width of the sansitive region of the photo-diode. The sensitive length of the diode was 2 mm and 16 the light traversed about 0.24 mm of an insensitive region beore reaching the sensitive region of the photodiode.
The p-i-n photodiode, with its electrodes attàched to an e~ternal bias voltage supply and signal detection circuits was then aligned with the light beam emitted from the optical fiber such that the maximum `~ electrical output signal was obtained from the photodiode.
A molybdenum tab was`used as a ~him be~ween the photodiode and the mounting block to obtain'the correct height for the detector. The photodiode was then bonded to the mount-~
ing block using an electrically conducting cuxable epoxyresin. ~he position of the photodiode was such that the light beam was propagated parallel to and in the pn ~unction plane o the photodiode.
The cap was then welded to the ring usin~
standard xesistance welding techniques.
' To obtain a measure of the improvement in detectox quantum e~iciency, the 1~06 micron wavelength light from a tungsten filament lamp tranæmitted through a narro~ band filter was first ~ocussed on a calibra~ed 86 photodiode, impinging on the calibrated photodiode normal to the pla~ne of the p-n junction. The calibrated photodiode was known to have a quantum efficiency of 24%
at 1.06~microns~ The light was then ocussed onto the end of the optical fiber external to the housing. ~he quantum efficiency of the optical fiber plus photodiode mounted : ' ':
' ' ' , ' in the housing was 36%. If the antireflection coating at 1.06 microns~is applied to the edge of the photodiode it is estimated that the quantum efficiency would increase 6 to ~bout 50~. If in addition an antireflection coating is applied to the ends of the optical fiber, ~hen it is estimated that the quantum efficiency for the device in the housing would increase to about 52%~
To show the effect of antireflection coatings, a drop of a light-transmitting curable epoxy resin was placed between and touching both the end of the optical fiber internal to the housing and the edge of the phato-diode. The measured quantum efficiency increased to about 45% from 36%.
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Claims (17)
1. An electro-optic device housing for fiber optic applications comprises:
a header;
an electro-optic device mounted on said header;
electrodes inserted through said header;
means for electrically connecting said electro-optic device to said electrodes;
a sidewall bonded to said header;
a fiber guide tube inserted in an opening in said sidewall bonded to said sidewall and extending only outward from said sidewall;
an optical fiber inserted in said fiber guide tube and extending from outside said sidewall, through and inside said sidewall towards said electro-optic device and bonded to said sidewall; and a cover plate bonded to said sidewall which encloses said electro-optic device, said electrodes and that portion of said optical fiber inside said sidewall.
a header;
an electro-optic device mounted on said header;
electrodes inserted through said header;
means for electrically connecting said electro-optic device to said electrodes;
a sidewall bonded to said header;
a fiber guide tube inserted in an opening in said sidewall bonded to said sidewall and extending only outward from said sidewall;
an optical fiber inserted in said fiber guide tube and extending from outside said sidewall, through and inside said sidewall towards said electro-optic device and bonded to said sidewall; and a cover plate bonded to said sidewall which encloses said electro-optic device, said electrodes and that portion of said optical fiber inside said sidewall.
2. An electro-optic device housing according to claim 1 wherein said electro-optic device is a light detector.
3. An electro-optic device housing according to claim 2 wherein said light detector is a photo-conductor.
4. An electro-optic device housing according to claim 2 wherein said light detector is a depletion layer photodiode.
5. An electro-optic device housing according to claim 4 wherein said depletion layer photodiode is a p-i-n photodiode.
6. An electro-optic device housing according to claim 2 wherein said light detector is an avalanche photodiode.
7. An electro-optic device housing according to claim 2 wherein said light detector is a p-n junction device and is oriented such that light emitted from the end of said optical fiber internal to said housing propagates parallel to and in the plane of the p-n junction of said light detector.
8. An electro-optic device housing according to claim 1 wherein said electro-optic device is a light source.
9. An electro-optic device housing according to claim 8 wherein said light source is a semiconductor pn junction light emitting diode.
10. An electro-optic device housing according to claim 8 wherein said light source is a semiconductor pn junction injection laser.
11. An electro-optic device housing according to claim 1 wherein said optical fiber has a numerical aperture between about 0.2 and about 0.7.
12. An electro-optic device housing according to claim 1 wherein said optical fiber has a numerical aperture between about 0.5 to about 0.7.
13. An electro-optic device housing according to claim 1 wherein said electro-optic device is bonded to a mounting block bonded to said header.
14. An electro-optic device housing according to claim 1 wherein said optical fiber is supported on a support block mounted on said header.
15. An electro-optic device housing according to claim 2 wherein said light detector is antireflection coated for the wavelength of an impinging light beam.
16. An electro-optic device housing according to claim 1 wherein the two opposed ends of said optical fiber are antireflection coated for the wavelength of an impinging light beam.
17. An electro-optic device housing according to claim 1 further comprising an electrical device mounted on said header and coupled to said electro-optic device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA311,434A CA1108900A (en) | 1978-09-15 | 1978-09-15 | Electro-optic device housing for fiber-optic applications |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA311,434A CA1108900A (en) | 1978-09-15 | 1978-09-15 | Electro-optic device housing for fiber-optic applications |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1108900A true CA1108900A (en) | 1981-09-15 |
Family
ID=4112372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA311,434A Expired CA1108900A (en) | 1978-09-15 | 1978-09-15 | Electro-optic device housing for fiber-optic applications |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1108900A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1984001057A1 (en) * | 1982-09-09 | 1984-03-15 | Plessey Overseas | Optical device |
| EP0111264A2 (en) * | 1982-12-03 | 1984-06-20 | Siemens Aktiengesellschaft | Transmitting or receiving apparatus for opto-electrical communication equipment |
| EP0111263A2 (en) * | 1982-12-03 | 1984-06-20 | Siemens Aktiengesellschaft | Transmitting or receiving apparatus containing a diode in a support |
| US4687290A (en) * | 1984-02-17 | 1987-08-18 | Siemens Aktiengesellschaft | Protective tube arrangement for a glass fiber |
| DE3606588A1 (en) * | 1986-02-28 | 1987-09-03 | Siemens Ag | Gas-tight feedthrough of a glass fibre |
| US4707066A (en) * | 1983-10-12 | 1987-11-17 | Siemens Aktiengesellschaft | Glass fiber bushing through a wall opening of a housing and method of manufacture |
| FR2607940A1 (en) * | 1986-12-04 | 1988-06-10 | Rca Corp | FIBER OPTICAL CABLE END |
| US4778241A (en) * | 1986-03-12 | 1988-10-18 | Siemens Aktiengesellschaft | Method for attaching and adjusting the end section of a glass fiber |
| EP0337141A1 (en) * | 1988-03-31 | 1989-10-18 | Siemens Aktiengesellschaft | Optical fiber feedthrough for optoelectronic modules and methods of its manufacturing |
| EP0445947A2 (en) * | 1990-03-05 | 1991-09-11 | Hughes Aircraft Company | Optoelectronic hybrid package assembly including integral, self-aligned fiber optic connector |
| US6793411B2 (en) | 2000-12-22 | 2004-09-21 | Nufern | Method and apparatus for communicating signals with an optical fiber |
-
1978
- 1978-09-15 CA CA311,434A patent/CA1108900A/en not_active Expired
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1984001057A1 (en) * | 1982-09-09 | 1984-03-15 | Plessey Overseas | Optical device |
| US4834490A (en) * | 1982-12-03 | 1989-05-30 | Siemens Aktiengesellschaft | Transmitting receiving device with a diode mounted on a support |
| EP0111264A2 (en) * | 1982-12-03 | 1984-06-20 | Siemens Aktiengesellschaft | Transmitting or receiving apparatus for opto-electrical communication equipment |
| EP0111263A2 (en) * | 1982-12-03 | 1984-06-20 | Siemens Aktiengesellschaft | Transmitting or receiving apparatus containing a diode in a support |
| EP0111264A3 (en) * | 1982-12-03 | 1984-08-08 | Siemens Aktiengesellschaft | Transmitting or receiving apparatus for opto-electrical communication equipment |
| EP0111263A3 (en) * | 1982-12-03 | 1984-08-08 | Siemens Aktiengesellschaft | Transmitting or receiving apparatus containing a diode in a support |
| US4707066A (en) * | 1983-10-12 | 1987-11-17 | Siemens Aktiengesellschaft | Glass fiber bushing through a wall opening of a housing and method of manufacture |
| US4687290A (en) * | 1984-02-17 | 1987-08-18 | Siemens Aktiengesellschaft | Protective tube arrangement for a glass fiber |
| DE3606588A1 (en) * | 1986-02-28 | 1987-09-03 | Siemens Ag | Gas-tight feedthrough of a glass fibre |
| US4778241A (en) * | 1986-03-12 | 1988-10-18 | Siemens Aktiengesellschaft | Method for attaching and adjusting the end section of a glass fiber |
| FR2607940A1 (en) * | 1986-12-04 | 1988-06-10 | Rca Corp | FIBER OPTICAL CABLE END |
| EP0337141A1 (en) * | 1988-03-31 | 1989-10-18 | Siemens Aktiengesellschaft | Optical fiber feedthrough for optoelectronic modules and methods of its manufacturing |
| US4902091A (en) * | 1988-03-31 | 1990-02-20 | Siemens Ag | Light waveguide feedthrough for optoelectronic modules and method for their manufacture |
| EP0445947A2 (en) * | 1990-03-05 | 1991-09-11 | Hughes Aircraft Company | Optoelectronic hybrid package assembly including integral, self-aligned fiber optic connector |
| EP0445947A3 (en) * | 1990-03-05 | 1992-05-27 | Hughes Aircraft Company | Optoelectronic hybrid package assembly including integral, self-aligned fiber optic connector |
| US6793411B2 (en) | 2000-12-22 | 2004-09-21 | Nufern | Method and apparatus for communicating signals with an optical fiber |
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| MKEX | Expiry |