EP0437963A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
An optical fiber filter
Assignee: AT&T Inc
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Filing: 1990-12-20
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Granted: —
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Expires: 2010-12-20
Abstract
Abstract A low loss, tunable optical filter (20) comprises two ferrules (24-24) which are aligned axially with each of two adjacent end faces being provided with a wafer (30). A mirror (40) is embedded between each end face and its associated wafer, the wafer being bonded to the end face of its associated wafer. Optical fiber is disposed in a passageway which extends through each ferrule and through the associated wafer. The ferrules and associated wafers are supported to cause adjacent exposed faces of the wafers to be in predetermined spatial relation to each other. Any gap therebetween may be fixed or may be adjusted by a piezoelectric transducer system (44). The disclosed filter provides rejection ratios which are sufficiently high for frequency discrimination in frequency shift keying systems and for channel selection or switching in wave division multiplexer applications.
Inventors
- 👤 Jane B. Clayton
- 👤 Calvin M. Miller
- 👤 William Anthony Vicory
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 16:25
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29379; G02B6/29395; G02B6/29346; G02B6/29358; G02B6/29359
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
195 words
An optical filter which is capable of having a desired bandwidth, said filter being characterized by a first ferrule assembly having aligned passageway portions for receiving an optical fiber, the passageway portions being spaced apart by a mirror which is transverse to a longitudinal axis of the passageway portions and which is substantially closer to one end of said first ferrule assembly than to an opposite end thereof; a second ferrule assembly having aligned passageway portions for receiving an optical fiber, the passageway portions in said second ferrule assembly being spaced apart by a mirror which is transverse to a longitudinal axis of said passageway portions in said second ferrule assembly, and which is substantially closer to one end of said second ferrule assembly than to an opposite end thereof; optical fiber positioned in each passageway portion of each ferrule assembly; and means for holding said first and second ferrule assemblies with the axes of the passageways aligned and with said one end of said first ferrule assembly being adjacent to said one end of said second ferrule assembly and for causing adjacent one ends of the ferrule assemblies to have a predetermined axial spacing.
Claim 2
Dependent Claim
84 words
The optical filter of claim 1, wherein each said ferrule assembly includes a wafer having a mirror deposited on one end surface thereof and covering only a portion of the area of the end surface and a ferrule which is bonded to said wafer to cause said mirror to be embedded between said wafer and said ferrule, the portion of the end surface of each wafer over which said mirror is formed including that portion of the end surface to which said passageway opens.
Claim 3
Dependent Claim
22 words
The optical filter of claim 2, wherein each layer of each mirror has a thickness equal to one quarter of a wavelength.
Claim 4
Dependent Claim
49 words
A tunable optical filter which includes the optical filter of claim 1, wherein a gap between adjacent one ends of said first and second ferrule assemblies is adjustable, said tunable optical filter also including means for adjusting the gap between end faces of said first and second ferrule assemblies.
Claim 5
Dependent Claim
85 words
The tunable optical filter of claim 4, wherein each said ferrule assembly includes a wafer having a mirror deposited on one end surface thereof and covering only a portion of the area of the end surface and a ferrule which is bonded to said wafer to cause said mirror to be embedded between said wafer and said ferrule, the portion of the end surface of each wafer over which said mirror is formed including that portion of the end surface to which said passageway opens.
Claim 6
Dependent Claim
23 words
The tunable optical filter of claim 5, wherein the finesse may be 100 or greater with an insertion loss not exceeding 3 dB.
Claim 7
Independent Claim
256 words
A method of making an optical filter, said method comprising the steps of providing two ferrule assemblies each of which is provided by a method comprising the steps of providing a pair of ferrules each of which includes a longitudinal extending passageway and a longitudinal axis, causing an optical fiber to be disposed in the passageway of each ferrule, said method of providing each ferrule assembly being characterized by the steps of causing a mirror to be formed on an end surface of one ferrule of [each] the pair such that the mirror covers the passageway which opens to the end surface; positioning the other ferrule of the pair with the one ferrule of the pair to cause the passageways to be aligned and to cause an end surface of the other ferrule to abut the mirrored end surface of the one ferrule; causing the other ferrule to become attached to the one ferrule of the pair in the aligned position to provide a ferrule assembly; and severing the one ferrule of the pair in a plane normal to the longitudinal axes of the ferrules at a distance from the mirror which is small relative to the length of the ferrule at a distance from the mirror which is small relative to the length of the ferrule to provide a wafer having a newly formed end surface; and positioning the two ferrule assemblies to align the passageways and to cause the spacing between the newly formed end surfaces of the wafers to be a predetermined value.
Claim 8
Dependent Claim
37 words
The method of claim 7, wherein the step of causing a mirror to be formed is accomplished to cause the mirror to cover only a portion of the transverse cross sectional area of each said one ferrule.
Claim 9
Dependent Claim
65 words
A method of making a tunable optical filter which comprises the steps set forth in claim 7 and which comprises the further step of mounting said ferrule assemblies for relative movement therebetween along the longitudinal axes and providing means for causing relative movement between said ferrule assemblies to cause the spacing between the newly formed end surfaces of the wafers to be a predetermined value.
Claim 10
Dependent Claim
84 words
An optical assembly adapted to be used in an optical filter which is capable of having a desired bandwidth, said assembly comprising: a ferrule assembly having aligned passageway portions for receiving an optical fiber, the passageway portions being spaced apart by a mirror which is transverse to a longitudinal axis of the passageway portions and which is substantially closer to one end of said ferrule assembly than to an opposite end thereof; and optical fiber positioned in each passageway portion of said ferrule assembly.
Claim 11
Dependent Claim
83 words
The optical filter of claim 10, wherein said ferrule assembly includes a wafer having a mirror deposited on one end surface thereof and covering only a portion of the area of the end surface and a ferrule which is bonded to said wafer to cause said mirror to be embedded between said wafer and said ferrule, the portion of the end surface of each wafer over which said mirror is formed including that portion of the end surface to which said passageway opens.
References Cited (Backward Citations)
No citation records indexed.
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