USRE36710E - Integrated tunable optical filter - Google Patents

Integrated tunable optical filter Download PDF

Info

Publication number
USRE36710E
USRE36710E US09/118,474 US11847498A USRE36710E US RE36710 E USRE36710 E US RE36710E US 11847498 A US11847498 A US 11847498A US RE36710 E USRE36710 E US RE36710E
Authority
US
United States
Prior art keywords
section
reflection
period
optical filter
wavelength
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 - Fee Related
Application number
US09/118,474
Inventor
Roel Baets
Jan Willems
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Interuniversitair Microelektronica Centrum vzw IMEC
Original Assignee
Interuniversitair Microelektronica Centrum vzw IMEC
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from US08/635,057 external-priority patent/US5621828A/en
Application filed by Interuniversitair Microelektronica Centrum vzw IMEC filed Critical Interuniversitair Microelektronica Centrum vzw IMEC
Priority to US09/118,474 priority Critical patent/USRE36710E/en
Application granted granted Critical
Publication of USRE36710E publication Critical patent/USRE36710E/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/29Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the position or the direction of light beams, i.e. deflection
    • G02F1/31Digital deflection, i.e. optical switching
    • G02F1/313Digital deflection, i.e. optical switching in an optical waveguide structure
    • G02F1/3132Digital deflection, i.e. optical switching in an optical waveguide structure of directional coupler type
    • G02F1/3133Digital deflection, i.e. optical switching in an optical waveguide structure of directional coupler type the optical waveguides being made of semiconducting materials
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2201/00Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
    • G02F2201/30Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 grating
    • G02F2201/307Reflective grating, i.e. Bragg grating
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2203/00Function characteristic
    • G02F2203/05Function characteristic wavelength dependent
    • G02F2203/055Function characteristic wavelength dependent wavelength filtering
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/10Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/1028Coupling to elements in the cavity, e.g. coupling to waveguides adjacent the active region, e.g. forward coupled [DFC] structures
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/10Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/1028Coupling to elements in the cavity, e.g. coupling to waveguides adjacent the active region, e.g. forward coupled [DFC] structures
    • H01S5/1032Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region
    • H01S5/1035Forward coupled structures [DFC]
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/10Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/12Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
    • H01S5/1206Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers having a non constant or multiplicity of periods
    • H01S5/1209Sampled grating

Definitions

  • the invention relates to an integrated broadly tunable optical filter designed, in particular, for advanced WDM (Wavelength Division Multiplexing) applications as well as for use in spectroscopic testing of various optical components.
  • WDM Widelength Division Multiplexing
  • tunable optical filters are key components in optical communication systems. Two objectives dominate with such filters. The aims, on the one hand, are a broad tunable range and, on the other hand, high spectral selectivity. The planar integrated structures known hitherto, however, permit only one of these objectives at a time to be met.
  • a conventional filter structure known as co-directional coupler structure, is described in "Broadly tunable InGaAsP/InP buried rib waveguide vertical coupler filter" (R. C. Alferness, L. L. Buhl, U. Koren, B. I. Miller, M. G. Young, T. L. Koch, G. A. Burrus, G. Raybon), Appl. Phys. Lett. 60(8), 24 Feb. 1992.
  • This conventional structure consists of two asymmetrical waveguides having different effective refractive indices. The optical signal launched into the uppermost waveguide is launched into the lowermost waveguide and selectively reflected towards the uppermost waveguide. If the parameters of the waveguides are chosen carefully, a structure of this type can act as a selective filter.
  • a semiconductor optical structure which can provide high selectivity.
  • This conventional structure makes use of a waveguide having a grating grown thereon, that grating of which is periodically omitted.
  • a structure of this type has already been used in a tunable laser (V. Jayaraman, D. A. Cohen, L. A. Coldten, "Demonstration of broadband tunability in a semiconductor laser using sampled gratings", Appl. Phys. Lett 60(19), 11 May 1992). Nevertheless, a structure of this type has hitherto not been used in a filter structure.
  • This conventional structure provides a comb-shaped reflection spectrum.
  • the parameters thereof are the spacing between the peaks, the spectral bandwidth of the envelope of the comb spectrum, the peak maximums and the bandwidth of a reflection peak. The latter is probably the most important parameter, because it affects the selectivity of the structure. Most unfortunately, this parameter too limits the tuning range of the structure.
  • the object of the present invention is to present an optical filter structure which provides, at the same time, a large tuning range and high spectral selectivity in a compact integrated appliance.
  • the present invention makes provision for an integrated optical filter which comprises a semiconductor substrate having a common electrode on a first side thereof, the substrate comprising a first waveguide on which a grating is grown, said grating comprising a first part having a large period and a second part having a small period, from which said grating is periodically omitted.
  • a second waveguide extends in such a way that there is formed, in a first section of the substrate, a codirectional coupler section. Said second waveguide is covered by a semiconductor part whose topside carries a second electrode.
  • a third electrode Provided on the topside of the substrate at the top of the second grating section there is a third electrode.
  • the refractive indices of both waveguides in the first section are controlled by current injection along said second electrode.
  • the refractive index of the waveguide in the second section is controlled by current injection along said third electrode.
  • FIG. 1 diagrammatically represents a cross section of the structure according to the invention
  • FIGS. 2 to 6 inclusive represent curves, by way of example, which illustrate the operation of the filter structure of FIG. 1.
  • FIG. 1 shows an optical filter structure according to the invention.
  • the integrated filter structure mainly comprises substrate 1 made of semiconductor material, for example InP, in which two sections 2 and 3 are formed. On the substrate a number of layers are grown from semiconductor material, for example InGaAsP, which form the lowermost waveguide 4 having a grating 40 grown thereon.
  • Said grating 40 is grown so as to have two different geometrical structures, namely a first rib-shaped structure 41 having a long period in said first section 2, and a second periodically broken sawtooth-shaped or stripe-shaped structure 42 in said second section 3.
  • the last mentioned sawtooth-shaped structure 42 is formed so as to have short-period striped regions 43 and alternating non-striped regions 44.
  • Typical values for the period of the rib-shaped structure range between 10 and 50 ⁇ m, inclusive. Typical values for the period of the sawtooth-shaped structure are below 1 ⁇ m.
  • an uppermost waveguide 5 extends in such a way that there is formed, in the first second 2 of the substrate, a codirectional coupler section.
  • a first electrode 6 On the topside of the first section 2 there is provided a first electrode 6, by means of which current injection can be coupled in into said first section.
  • a second electrode 7 On the topside of the second section 3, too, a second electrode 7 is provided by means of which current injection can be coupled in into said second section.
  • a common back electrode 8 is provided on the underside of the substrate.
  • An appliance according to the invention works as follows.
  • An optical signal is passed into the uppermost waveguide 5, and at a certain wavelength ⁇ , 100% of the optical power is coupled across to the lowermost waveguide 4.
  • the spectral bandwidth of the codirectional coupler in section 2 is determined by the length L codir of said section 2, the period of the rib-shaped structure 41 and the effective refractive indices n 2 , and n b of the two waveguides 5 and 4, respectively, according to the following relationship: ##EQU1##
  • Said coupled wavelength can be altered by varying the refractive indices n a and n b based on current injection by applying a voltage between electrodes 6 and 8.
  • FIG. 2 represents an example of a filter response A of a codirectional coupler
  • FIG. 3 represents the same filter response A', but shifted in wavelength by current injection. It should be noted that the filter response in section 2 has a low selectivity.
  • the optical signal which was coupled to the lowermost waveguide 4 ends up in the broken sawtooth-shaped structure 42.
  • the reflection spectrum of said structure is comb-shaped as shown by B in FIG. 4, together with the filter response of the first section.
  • the reflection peaks of the comb spectrum have a high selectivity.
  • the selectivity is mainly determined by the number of periods in the broken structure 42 and the coupling strength of that structure.
  • the reflection peaks of the comb spectrum B can be changed slightly by current injection in said section when a voltage is applied between electrodes 7 and 8.
  • the Comb spectrum is slightly shifted in wavelength as shown by B' in FIG. 5.
  • the wavelength of one of the reflection peaks corresponds to the central coupling wavelength of the first section 2.
  • the parameters of the two sections 2 and 3 cannot be chosen totally independently of one another, but must satisfy at least the following condition.
  • This condition establishes a relationship between the spectral bandwidth of the codirectional coupler and the spacing between the peaks in the comb spectrum of section 3. This bandwidth must be smaller than the spacing between the peaks: ##EQU2## where ⁇ 3db is the spectral bandwidth of the codirectional coupler: ##EQU3## where: ⁇ is the wavelength
  • is the period of the rib-shaped structure in the first section
  • L codir is the length of the first section
  • n a , n b are the effective refractive indices of the two waveguides in the first section
  • L 1 is the length of the sawtooth-shaped structure grating in one period of the second section
  • L 2 is the length of the non-striped portion of the grating structure in one period of the second section
  • n is the effective refractive index of the waveguide in the second section.
  • the tuning range is determined by both sections and is no greater than the maximum of two variables, namely ⁇ 1 , the tuning range of the codirectional structure, and ⁇ 2 , the spectral bandwidth of the envelope of the comb spectrum at the second section 3. ##EQU4##

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Integrated Circuits (AREA)
  • Lasers (AREA)
  • Semiconductor Lasers (AREA)

Abstract

An integrated tunable optical filter comprising a substrate made of a semiconducting material. The substrate includes first and second sections. The first section forms a tunable transmission filter, based on a codirectional coupler having a low selectivity. The second section forms a reflection filter with a reflection spectrum containing a number of peaks. A first injector, designed for current injection into said first section, is provided. Thus, the filter response of the first section is shifted in wavelength over a large wavelength range. There is also a second injector, designed for current injection into the second section. As a result, the reflective spectrum of the second section is slightly shifted in wavelength, in such a way that one reflection peak of the reflection spectrum corresponds to the coupling wavelength of the first section. Consequently, the total filter response has a very narrow bandwidth and wide tunability.

Description

This application is continuation application of Ser. No. 08/244,110, as PCT/BE93/00061, Sep. 17, 1993 published as WO94/07178, Mar. 31, 1994, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to an integrated broadly tunable optical filter designed, in particular, for advanced WDM (Wavelength Division Multiplexing) applications as well as for use in spectroscopic testing of various optical components.
Broadly tunable optical filters are key components in optical communication systems. Two objectives dominate with such filters. The aims, on the one hand, are a broad tunable range and, on the other hand, high spectral selectivity. The planar integrated structures known hitherto, however, permit only one of these objectives at a time to be met.
A conventional filter structure, known as co-directional coupler structure, is described in "Broadly tunable InGaAsP/InP buried rib waveguide vertical coupler filter" (R. C. Alferness, L. L. Buhl, U. Koren, B. I. Miller, M. G. Young, T. L. Koch, G. A. Burrus, G. Raybon), Appl. Phys. Lett. 60(8), 24 Feb. 1992. This conventional structure consists of two asymmetrical waveguides having different effective refractive indices. The optical signal launched into the uppermost waveguide is launched into the lowermost waveguide and selectively reflected towards the uppermost waveguide. If the parameters of the waveguides are chosen carefully, a structure of this type can act as a selective filter.
The advantage of this conventional structure is the fact that a broad tuning range is provided, but it is difficult to obtain high spectral selectivity without constructing a long appliance.
On the other hand, a semiconductor optical structure is also known which can provide high selectivity. This conventional structure makes use of a waveguide having a grating grown thereon, that grating of which is periodically omitted. A structure of this type has already been used in a tunable laser (V. Jayaraman, D. A. Cohen, L. A. Coldten, "Demonstration of broadband tunability in a semiconductor laser using sampled gratings", Appl. Phys. Lett 60(19), 11 May 1992). Nevertheless, a structure of this type has hitherto not been used in a filter structure.
This conventional structure provides a comb-shaped reflection spectrum. The parameters thereof are the spacing between the peaks, the spectral bandwidth of the envelope of the comb spectrum, the peak maximums and the bandwidth of a reflection peak. The latter is probably the most important parameter, because it affects the selectivity of the structure. Most unfortunately, this parameter too limits the tuning range of the structure.
SUMMARY OF THE INVENTION
The object of the present invention is to present an optical filter structure which provides, at the same time, a large tuning range and high spectral selectivity in a compact integrated appliance.
In order to accomplish the abovementioned objective, the present invention makes provision for an integrated optical filter which comprises a semiconductor substrate having a common electrode on a first side thereof, the substrate comprising a first waveguide on which a grating is grown, said grating comprising a first part having a large period and a second part having a small period, from which said grating is periodically omitted. At the top of said first grating section and at a distance therefrom, a second waveguide extends in such a way that there is formed, in a first section of the substrate, a codirectional coupler section. Said second waveguide is covered by a semiconductor part whose topside carries a second electrode. Provided on the topside of the substrate at the top of the second grating section there is a third electrode. The refractive indices of both waveguides in the first section are controlled by current injection along said second electrode. The refractive index of the waveguide in the second section is controlled by current injection along said third electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail with reference to the drawing, in which
FIG. 1 diagrammatically represents a cross section of the structure according to the invention;
FIGS. 2 to 6 inclusive represent curves, by way of example, which illustrate the operation of the filter structure of FIG. 1.
DETAILED DESCRIPTION
FIG. 1 shows an optical filter structure according to the invention. The integrated filter structure mainly comprises substrate 1 made of semiconductor material, for example InP, in which two sections 2 and 3 are formed. On the substrate a number of layers are grown from semiconductor material, for example InGaAsP, which form the lowermost waveguide 4 having a grating 40 grown thereon. Said grating 40 is grown so as to have two different geometrical structures, namely a first rib-shaped structure 41 having a long period in said first section 2, and a second periodically broken sawtooth-shaped or stripe-shaped structure 42 in said second section 3. The last mentioned sawtooth-shaped structure 42 is formed so as to have short-period striped regions 43 and alternating non-striped regions 44. Typical values for the period of the rib-shaped structure range between 10 and 50 μm, inclusive. Typical values for the period of the sawtooth-shaped structure are below 1 μm.
At the top of the first rib-shaped structure 41, and at a distance thereof, an uppermost waveguide 5 extends in such a way that there is formed, in the first second 2 of the substrate, a codirectional coupler section. On the topside of the first section 2 there is provided a first electrode 6, by means of which current injection can be coupled in into said first section. On the topside of the second section 3, too, a second electrode 7 is provided by means of which current injection can be coupled in into said second section. A common back electrode 8 is provided on the underside of the substrate.
An appliance according to the invention works as follows. An optical signal is passed into the uppermost waveguide 5, and at a certain wavelength λ, 100% of the optical power is coupled across to the lowermost waveguide 4. The spectral bandwidth of the codirectional coupler in section 2 is determined by the length Lcodir of said section 2, the period of the rib-shaped structure 41 and the effective refractive indices n2, and nb of the two waveguides 5 and 4, respectively, according to the following relationship: ##EQU1##
Said coupled wavelength can be altered by varying the refractive indices na and nb based on current injection by applying a voltage between electrodes 6 and 8. FIG. 2 represents an example of a filter response A of a codirectional coupler, and FIG. 3 represents the same filter response A', but shifted in wavelength by current injection. It should be noted that the filter response in section 2 has a low selectivity.
The optical signal which was coupled to the lowermost waveguide 4 ends up in the broken sawtooth-shaped structure 42. The reflection spectrum of said structure is comb-shaped as shown by B in FIG. 4, together with the filter response of the first section. The reflection peaks of the comb spectrum have a high selectivity. The selectivity is mainly determined by the number of periods in the broken structure 42 and the coupling strength of that structure.
The reflection peaks of the comb spectrum B can be changed slightly by current injection in said section when a voltage is applied between electrodes 7 and 8. Thus the Comb spectrum is slightly shifted in wavelength as shown by B' in FIG. 5. Thus it is possible to ensure that the wavelength of one of the reflection peaks corresponds to the central coupling wavelength of the first section 2.
This results in a filter response C having a very narrow bandwidth as shown in FIG. 6, which response is launched into the uppermost waveguide 5 and supplied to the output thereof.
The parameters of the two sections 2 and 3 cannot be chosen totally independently of one another, but must satisfy at least the following condition. This condition establishes a relationship between the spectral bandwidth of the codirectional coupler and the spacing between the peaks in the comb spectrum of section 3. This bandwidth must be smaller than the spacing between the peaks: ##EQU2## where Δλ3db is the spectral bandwidth of the codirectional coupler: ##EQU3## where: λ is the wavelength,
Δ is the period of the rib-shaped structure in the first section
Lcodir is the length of the first section
na, nb are the effective refractive indices of the two waveguides in the first section,
L1 is the length of the sawtooth-shaped structure grating in one period of the second section,
L2 is the length of the non-striped portion of the grating structure in one period of the second section,
n is the effective refractive index of the waveguide in the second section.
Furthermore, the choice of the parameters is also restricted by the properties required of the overall structure. Two important properties are the magnitude of the tuning range and the selectivity. The tuning range is determined by both sections and is no greater than the maximum of two variables, namely Δλ1, the tuning range of the codirectional structure, and Δλ2, the spectral bandwidth of the envelope of the comb spectrum at the second section 3. ##EQU4##
Typical values in one illustrative embodiment in an InGaAsP substrate:
______________________________________                                    
Codirectional coupler section                                             
Length L.sub.coupler   900 μm                                          
                       3.210                                              
                       3.307                                              
Å                  16 μM                                           
Coupling coefficient   17.5 cm.sup.-1                                     
Broken sawtooth-shaped structure                                          
Length                 900 μm                                          
N.sub.eff              3.24                                               
L.sub.1                75 μm                                           
L.sub.2                7.5 μm                                          
                       0.2413 μm                                       
Coupling coefficient   10 cm.sup.-1                                       
Filter response                                                           
Central wavelength      = 1.550 μm                                     
Tuning range           50 nm                                              
Change of refractive index                                                
                       0.3 nm                                             
______________________________________                                    

Claims (7)

We claim:
1. An integrated tunable optical filter comprising:
a substrate made of semiconducting material,
a first section on said substrate forming a transmission filter having a low spectral selectivity, said first section including a first waveguide system with upper and lower waveguides, a periodic rib shaped structure .[.between said upper and lower.]. .Iadd.adjacent at least one of said .Iaddend.waveguides defining a filter response with a central coupling wavelength, and
a second section on said substrate forming a reflector with a spectral reflection with a plurality of reflection peaks, said second section including a second waveguide coupled with said .[.lower.]. .Iadd.first .Iaddend.waveguide .Iadd.system .Iaddend.in said first section and having a periodically broken short-period reflection structure including short period stripped regions alternating with non-stripped regions;
first means for injecting current into said first section, said filter response of said first section being shifted in wavelength over a range covering a plurality of said reflection peaks of said second section; and
second means for injecting current into said second section, said reflection spectrum of said second section being shifted in wavelength and one reflection peak of said plurality of reflection peaks corresponding to said central coupling wavelength of said first section;
wherein said optical filter has a reflection response .[.in said upper waveguide.]. with a narrow bandwidth and wide tunability.
2. An optical filter according to claim 1, wherein said .[.second.]. .Iadd.first .Iaddend.and second waveguides are formed in a single layer interface.
3. An optical filter according to claim 1, wherein said first section forms a codirectional optical coupler.
4. An optical filter according to claim 3, wherein said short-period reflection structure and said rib-shaped structure are formed in a single layer interface.
5. An optical filter according to claim 3, wherein said rib-shaped structure has a period of 10-50 μm.
6. An optical filter according to claim 5, wherein said short-period reflection structure is sawtooth-shaped.
7. An optical filter according to claim 5, wherein said short-period reflection structure and said rib-shaped structure each have a period and wherein said short period reflection structure has a period less than said period of said rib-shaped structure.
US09/118,474 1992-09-14 1998-07-17 Integrated tunable optical filter Expired - Fee Related USRE36710E (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US09/118,474 USRE36710E (en) 1992-09-14 1998-07-17 Integrated tunable optical filter

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
BE09200838 1992-09-14
BE9200838A BE1006207A3 (en) 1992-09-24 1992-09-24 INTEGRATED tunable optical FILTER.
US08/635,057 US5621828A (en) 1992-09-24 1996-04-19 Integrated tunable optical filter
US09/118,474 USRE36710E (en) 1992-09-14 1998-07-17 Integrated tunable optical filter

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US08/635,057 Reissue US5621828A (en) 1992-09-14 1996-04-19 Integrated tunable optical filter

Publications (1)

Publication Number Publication Date
USRE36710E true USRE36710E (en) 2000-05-23

Family

ID=3886455

Family Applications (1)

Application Number Title Priority Date Filing Date
US09/118,474 Expired - Fee Related USRE36710E (en) 1992-09-14 1998-07-17 Integrated tunable optical filter

Country Status (7)

Country Link
US (1) USRE36710E (en)
EP (1) EP0613571B1 (en)
JP (1) JP3185930B2 (en)
AT (1) ATE169127T1 (en)
BE (1) BE1006207A3 (en)
DE (1) DE69320022T2 (en)
WO (1) WO1994007178A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030128724A1 (en) * 2001-09-10 2003-07-10 Imec Vzw Widely tunable twin guide laser structure
US6665474B2 (en) 2001-02-22 2003-12-16 Altitun Ab Method of improving selectivity in a tunable waveguide filter
US6904065B2 (en) 2001-02-22 2005-06-07 Adc Telecommunications, Inc. Method and apparatus for compensating losses in a tunable laser filter
US7023886B2 (en) 2001-11-08 2006-04-04 Intel Corporation Wavelength tunable optical components

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6674929B2 (en) * 2001-06-01 2004-01-06 Lightcross, Inc. Tunable optical filter
US6810168B1 (en) 2002-05-30 2004-10-26 Kotura, Inc. Tunable add/drop node
US20220171105A1 (en) * 2020-09-11 2022-06-02 Board Of Regents, The University Of Texas System Resonant filters having simultaneously tuned central wavelengths and sidebands

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4743087A (en) * 1984-06-07 1988-05-10 Kokusai Denshin Denwa Kabushiki Kaisha Optical external modulation semiconductor element
US4976513A (en) * 1987-11-11 1990-12-11 Nec Corporation Tunable wavelength filter
JPH0479287A (en) * 1990-07-20 1992-03-12 Canon Inc Tunable semiconductor laser
US5147825A (en) * 1988-08-26 1992-09-15 Bell Telephone Laboratories, Inc. Photonic-integrated-circuit fabrication process
US5189714A (en) * 1990-09-28 1993-02-23 Oki Electric Industry Co., Ltd. Optical wavelength filter device
US5220573A (en) * 1989-03-10 1993-06-15 Canon Kabushiki Kaisha Optical apparatus using wavelength selective photocoupler
US5253314A (en) * 1992-01-31 1993-10-12 At&T Bell Laboratories Tunable optical waveguide coupler
US5325392A (en) * 1992-03-06 1994-06-28 Nippon Telegraph And Telephone Corporation Distributed reflector and wavelength-tunable semiconductor laser
US5416866A (en) * 1992-08-26 1995-05-16 Telefonaktiebolaget L M Ericsson Optical waveguide/grating device for filtering optical wavelengths

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4743087A (en) * 1984-06-07 1988-05-10 Kokusai Denshin Denwa Kabushiki Kaisha Optical external modulation semiconductor element
US4976513A (en) * 1987-11-11 1990-12-11 Nec Corporation Tunable wavelength filter
US5147825A (en) * 1988-08-26 1992-09-15 Bell Telephone Laboratories, Inc. Photonic-integrated-circuit fabrication process
US5220573A (en) * 1989-03-10 1993-06-15 Canon Kabushiki Kaisha Optical apparatus using wavelength selective photocoupler
JPH0479287A (en) * 1990-07-20 1992-03-12 Canon Inc Tunable semiconductor laser
US5189714A (en) * 1990-09-28 1993-02-23 Oki Electric Industry Co., Ltd. Optical wavelength filter device
US5253314A (en) * 1992-01-31 1993-10-12 At&T Bell Laboratories Tunable optical waveguide coupler
US5325392A (en) * 1992-03-06 1994-06-28 Nippon Telegraph And Telephone Corporation Distributed reflector and wavelength-tunable semiconductor laser
US5416866A (en) * 1992-08-26 1995-05-16 Telefonaktiebolaget L M Ericsson Optical waveguide/grating device for filtering optical wavelengths

Non-Patent Citations (15)

* Cited by examiner, † Cited by third party
Title
Alferness et al, "Broadly tunable InGaAsP/InP buried rib waveguide vertical coupler filter", Appl. Phys. Lett. 60(8), pp. 980-982, Feb. 1992.
Alferness et al, Broadly tunable InGaAsP/InP buried rib waveguide vertical coupler filter , Appl. Phys. Lett. 60(8), pp. 980 982, Feb. 1992. *
Hirata et al, "Monolithic resonant optical reflector laser diodes", Electronics Letters, vol. 27, No. 22, pp. 2050-2051, Oct. 1991.
Hirata et al, Monolithic resonant optical reflector laser diodes , Electronics Letters, vol. 27, No. 22, pp. 2050 2051, Oct. 1991. *
IEEE Photonics Technology Letters, vol. 5, No. 7, Jul. 1993, M. Oberg et al, "74 mm wavelength tuning range of an InGaAsP/InP vertical grating assisted codirectionsl coupler laser . . . " (p. 735).
IEEE Photonics Technology Letters, vol. 5, No. 7, Jul. 1993, M. Oberg et al, 74 mm wavelength tuning range of an InGaAsP/InP vertical grating assisted codirectionsl coupler laser . . . (p. 735). *
Jayarman et al. "Demonstration of broadband tunability in a semiconductor laser using sampled gratings", Appl. Phys. Lett. 60(19), pp.2321-2323 May 1992.
Jayarman et al. Demonstration of broadband tunability in a semiconductor laser using sampled gratings , Appl. Phys. Lett. 60(19), pp.2321 2323 May 1992. *
Olsson et al, "Performance characteristics of a 1.5 um single frequency semiconductor laser with an external waveguide Bragg reflector", IEEE J. of Quantum Elec., vol. 24, No. 2, pp. 143-147, Feb. 1988.
Olsson et al, Performance characteristics of a 1.5 um single frequency semiconductor laser with an external waveguide Bragg reflector , IEEE J. of Quantum Elec., vol. 24, No. 2, pp. 143 147, Feb. 1988. *
Willems et al, "Novel widely tunable integrated optical filter with high spectral selectivity", 18th European Conference on Optical Communication Oct. 1992.
Willems et al, Novel widely tunable integrated optical filter with high spectral selectivity , 18th European Conference on Optical Communication Oct. 1992. *
Willens et al, Novel widley tunable integrated optical filter with high spectral selectivity, 18th European Conference on Optical Communication, Oct. 1992. *
Yayaraman et al, "Demonstration of broadband tunability in a semiconductor laser using sampled gratings", Appl. Phys. Lett. 60(19), pp. 2321-2323, May 1992.
Yayaraman et al, Demonstration of broadband tunability in a semiconductor laser using sampled gratings , Appl. Phys. Lett. 60(19), pp. 2321 2323, May 1992. *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6665474B2 (en) 2001-02-22 2003-12-16 Altitun Ab Method of improving selectivity in a tunable waveguide filter
US6904065B2 (en) 2001-02-22 2005-06-07 Adc Telecommunications, Inc. Method and apparatus for compensating losses in a tunable laser filter
US20030128724A1 (en) * 2001-09-10 2003-07-10 Imec Vzw Widely tunable twin guide laser structure
US7653093B2 (en) * 2001-09-10 2010-01-26 Imec Widely tunable twin guide laser structure
US7023886B2 (en) 2001-11-08 2006-04-04 Intel Corporation Wavelength tunable optical components

Also Published As

Publication number Publication date
DE69320022D1 (en) 1998-09-03
JP3185930B2 (en) 2001-07-11
WO1994007178A1 (en) 1994-03-31
DE69320022T2 (en) 1999-03-25
ATE169127T1 (en) 1998-08-15
EP0613571A1 (en) 1994-09-07
EP0613571B1 (en) 1998-07-29
BE1006207A3 (en) 1994-06-07
JPH07501628A (en) 1995-02-16

Similar Documents

Publication Publication Date Title
US5621828A (en) Integrated tunable optical filter
CA1115402A (en) Tunable optical waveguide directional coupler filter
EP1413023B1 (en) Tuneable laser
US5459799A (en) Tunable optical filter
US5333219A (en) Asymmetric Y-branch optical device
US4794346A (en) Broadband semiconductor optical amplifier structure
US6041071A (en) Electro-optically tunable external cavity mirror for a narrow linewidth semiconductor laser
EP0556952A1 (en) Wavelength selective coupler
JPH04211220A (en) Optical filter
US20040136415A1 (en) Tunable semiconductor laser and method thereof
US5748660A (en) Sample grating distributed bragg reflector laser, very widely matchable by phase variation and process for using this laser
US6101302A (en) Grating-assisted vertical codirectional coupler having pair grating structure
US5022038A (en) Wavelength tunable diode laser
USRE36710E (en) Integrated tunable optical filter
US6424763B1 (en) Tunable add/drop filter using side-coupled resonant tunneling
EP0316194B1 (en) A tunable wavelength filter
JPH0992933A (en) Wavelength changeable semiconductor laser
JPS61255085A (en) Semiconductor laser device
WO2002044780A1 (en) Grating assisted asymmetric directional coupler
EP1058358B1 (en) Tunable integrated semiconductor laser apparatus
US5084897A (en) Optical filter device
KR100277698B1 (en) Grating-assisted codirectional vertical coupler semiconductor optical filter
US20020064344A1 (en) Optical coupling device
JPH07174928A (en) Optical wavelength filter
US20020093995A1 (en) Electro-optically tunable external cavity mirror for a narrow linewidth semiconductor laser

Legal Events

Date Code Title Description
FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees