Nothing Special   »   [go: up one dir, main page]

GB2131971A - Positioning an optical fibre relative to an opto-electronic device - Google Patents

Positioning an optical fibre relative to an opto-electronic device Download PDF

Info

Publication number
GB2131971A
GB2131971A GB08235570A GB8235570A GB2131971A GB 2131971 A GB2131971 A GB 2131971A GB 08235570 A GB08235570 A GB 08235570A GB 8235570 A GB8235570 A GB 8235570A GB 2131971 A GB2131971 A GB 2131971A
Authority
GB
United Kingdom
Prior art keywords
tube
optical fibre
opto
soldering
positioning
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.)
Granted
Application number
GB08235570A
Other versions
GB2131971B (en
Inventor
Ronald Bicknell
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.)
Plessey Co Ltd
Original Assignee
Plessey Co Ltd
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
Application filed by Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB08235570A priority Critical patent/GB2131971B/en
Publication of GB2131971A publication Critical patent/GB2131971A/en
Application granted granted Critical
Publication of GB2131971B publication Critical patent/GB2131971B/en
Expired legal-status Critical Current

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
    • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
    • G02B6/4236—Fixing or mounting methods of the aligned elements
    • 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
    • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
    • G02B6/4236—Fixing or mounting methods of the aligned elements
    • G02B6/4238—Soldering
    • 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
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
    • G02B6/422—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements
    • G02B6/4225—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements by a direct measurement of the degree of coupling, e.g. the amount of light power coupled to the fibre or the opto-electronic element
    • 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
    • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
    • G02B6/4236—Fixing or mounting methods of the aligned elements
    • G02B6/4237—Welding

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Couplings Of Light Guides (AREA)

Abstract

An optical fibre A is aligned extremely accurately with an opto- electronic device, such as a laser L by securing the fibre within a metallic tube B and securing the metal tube to a cross arm C, manoeuvring the cross arm between two fixed posts D to give the optimum light output and soldering the cross arm to the posts to produce a rigid structure which is suitable for a hermetically sealed device. The tube B may be held by a micromanipulator at point X and then point Y during positioning. <IMAGE>

Description

SPECIFICATION Positioning devices The present invention relates to a positioning device and more particularly to a device for positioning on optical fibre accurately with respect to an opto-electronic device.
The present invention is particularly suited to the alignment of monomode fibres to solid state lasers and it is an object of the present invention to provide an accurate alignment means for aligning an optical fibre to a solid state laser or another opto-electronic device, which means is suitable for use in hermetically sealed environments.
According to the present invention there is provided a positioning device for positioning an optical fibre with respect to an opto-electronic device in which the opto-electronic device is fixed to a substrate and in which one or more support members are positioned across the optical fibre such that when the optical fibre has been positioned accurately with respect to the opto-electronic device it is secured to the one or more support members.
Preferably the support members are metallic bars and the optical fibre is supported within a metallic tube which is soldered to one or more support members.
The metallic tube may be soldered to two support members in a first embodiment or to a single support member and to the wall of an enclosure for the substrate in a second embodiment.
In said second embodiment the wall of the enclosure for the substrate may be provided with an oversize hole for the metallic tube, final positioning of the tube being obtained by movement of the tube within the oversized hole prior to securing the tube in the hole preferably b soldering or welding.
In a particular embodiment the optical fibre is a monomode fibre which is attached to the metal tube by soldering and the opto-electronic device is a solid state laser.
Embodiments of the present invention will now be described with reference to the accompanying drawing which shows a solid state laser in alignment with a monomode optical fibre. To align monomode fibres to solid state lasers the fibre tip must be positioned to micron accuracy in three dimensions. Commercial requirements are for rigidity, non-creep characteristics, and solvent free fixing methods suitable for hermetically sealed packages. Soldering techniques appear to be the most acceptable method of fixing the fibres, but it is necessary to overcome some of the drawbacks to using solder. Since soldering is essentially a high temperature process it is necessary to keep heat away from the heatsink and laser which for correct alignment must be working as a laser at not above room temperature.Secondly there is considerable thermal contraction of solder during solidification so the amount of solder must be minimised.
This invention seeks to nullify these effects by moving the soldered joints away from the fibre tip and to allow for positional adjustment after soldering.
In its present form the optical fibre (A) either cleaved or lens ended is suitably sealed with a soldering technique into a rigid small diameter tube (B) which has one or more crosspieces (C) welded or brazed to it along its length. These crosspieces are soldered to mounting pins (D) on the metal package (P) or on a substrate on which the laser (L) is mounted, the substrate being rigidly secured to the metal package (P) whilst the metal tube (B) is held rigidly in position by a micromanipulator holding the tube at or about the point X such that the fibre is in such a position to obtain the maximum coupling with the laser (L). After the first soldering the micro-manipulator is removed to a point (Y) and any small misalignment corrected using the crosspiece (C1) as a pivot.When maximum coupled power is again achieved either the second crosspiece (C2) is soldered to supporting pins, or the metal tube is soldered directly to the package at the exit point where a slightly oversize hole is provided to allow small movements. It has been found in practice that either technique is suitable.
The advantages of this invention are that there is an absence of solvent or epoxy resins making the technique suitable for hermetically sealed packages. The alignment can be accomplished relatively quickly by the soldering technique and fine adjustment can be provided following the first soldering. The alignment can be carried out with the laser running because no heat is transferred to the laser. The completed structure is extremely rigid and robust and can be designed to fit most packages.
1. A positioning device for positioning an optical fibre with respect to an opto-electronic device in which the opto-electronic device is fixed to a substrate and in which one or more support members are positioned across the optical fibre such that when the optical fibre has been positioned accurately with respect to the opto-electronic device it is secured to the one or more support members.
2. A positioning device as claimed in claim 1 in which the support members are metallic bars and the optical fibre is supported within a metallic tube which is soldered to one or more support members.
3. A positioning device as claimed in claim 2 in which the metallic tube is soldered to two support members.
4. A positioning device as claimed in claim 2 in which the metallic tube is soldered
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Positioning devices The present invention relates to a positioning device and more particularly to a device for positioning on optical fibre accurately with respect to an opto-electronic device. The present invention is particularly suited to the alignment of monomode fibres to solid state lasers and it is an object of the present invention to provide an accurate alignment means for aligning an optical fibre to a solid state laser or another opto-electronic device, which means is suitable for use in hermetically sealed environments. According to the present invention there is provided a positioning device for positioning an optical fibre with respect to an opto-electronic device in which the opto-electronic device is fixed to a substrate and in which one or more support members are positioned across the optical fibre such that when the optical fibre has been positioned accurately with respect to the opto-electronic device it is secured to the one or more support members. Preferably the support members are metallic bars and the optical fibre is supported within a metallic tube which is soldered to one or more support members. The metallic tube may be soldered to two support members in a first embodiment or to a single support member and to the wall of an enclosure for the substrate in a second embodiment. In said second embodiment the wall of the enclosure for the substrate may be provided with an oversize hole for the metallic tube, final positioning of the tube being obtained by movement of the tube within the oversized hole prior to securing the tube in the hole preferably b soldering or welding. In a particular embodiment the optical fibre is a monomode fibre which is attached to the metal tube by soldering and the opto-electronic device is a solid state laser. Embodiments of the present invention will now be described with reference to the accompanying drawing which shows a solid state laser in alignment with a monomode optical fibre. To align monomode fibres to solid state lasers the fibre tip must be positioned to micron accuracy in three dimensions. Commercial requirements are for rigidity, non-creep characteristics, and solvent free fixing methods suitable for hermetically sealed packages. Soldering techniques appear to be the most acceptable method of fixing the fibres, but it is necessary to overcome some of the drawbacks to using solder. Since soldering is essentially a high temperature process it is necessary to keep heat away from the heatsink and laser which for correct alignment must be working as a laser at not above room temperature.Secondly there is considerable thermal contraction of solder during solidification so the amount of solder must be minimised. This invention seeks to nullify these effects by moving the soldered joints away from the fibre tip and to allow for positional adjustment after soldering. In its present form the optical fibre (A) either cleaved or lens ended is suitably sealed with a soldering technique into a rigid small diameter tube (B) which has one or more crosspieces (C) welded or brazed to it along its length. These crosspieces are soldered to mounting pins (D) on the metal package (P) or on a substrate on which the laser (L) is mounted, the substrate being rigidly secured to the metal package (P) whilst the metal tube (B) is held rigidly in position by a micromanipulator holding the tube at or about the point X such that the fibre is in such a position to obtain the maximum coupling with the laser (L). After the first soldering the micro-manipulator is removed to a point (Y) and any small misalignment corrected using the crosspiece (C1) as a pivot.When maximum coupled power is again achieved either the second crosspiece (C2) is soldered to supporting pins, or the metal tube is soldered directly to the package at the exit point where a slightly oversize hole is provided to allow small movements. It has been found in practice that either technique is suitable. The advantages of this invention are that there is an absence of solvent or epoxy resins making the technique suitable for hermetically sealed packages. The alignment can be accomplished relatively quickly by the soldering technique and fine adjustment can be provided following the first soldering. The alignment can be carried out with the laser running because no heat is transferred to the laser. The completed structure is extremely rigid and robust and can be designed to fit most packages. CLAIMS
1. A positioning device for positioning an optical fibre with respect to an opto-electronic device in which the opto-electronic device is fixed to a substrate and in which one or more support members are positioned across the optical fibre such that when the optical fibre has been positioned accurately with respect to the opto-electronic device it is secured to the one or more support members.
2. A positioning device as claimed in claim 1 in which the support members are metallic bars and the optical fibre is supported within a metallic tube which is soldered to one or more support members.
3. A positioning device as claimed in claim 2 in which the metallic tube is soldered to two support members.
4. A positioning device as claimed in claim 2 in which the metallic tube is soldered to a single support member and to a wall of an enclosure within which the opto-electronic is positioned.
5. A positioning device as claimed in claim 4 in which the wall of the enclosure is provided with an oversize hole for the metallic tube, final positioning of the tube being obtained by movement of the tube within the oversized hole prior to securing the tube in the hole.
6. A positioning device as claimed in claim 2 in which the optical fibre is a mono mude type which is attached to the metallic tube by soldering.
7. A positioning device as claimed in claim 1 in which the opto-electronic is a solid state laser.
8. A positioning device substantially as described with reference to the accompanying drawing.
GB08235570A 1982-12-14 1982-12-14 Positioning an optical fibre relative to an opto-electronic device Expired GB2131971B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08235570A GB2131971B (en) 1982-12-14 1982-12-14 Positioning an optical fibre relative to an opto-electronic device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08235570A GB2131971B (en) 1982-12-14 1982-12-14 Positioning an optical fibre relative to an opto-electronic device

Publications (2)

Publication Number Publication Date
GB2131971A true GB2131971A (en) 1984-06-27
GB2131971B GB2131971B (en) 1986-12-10

Family

ID=10534960

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08235570A Expired GB2131971B (en) 1982-12-14 1982-12-14 Positioning an optical fibre relative to an opto-electronic device

Country Status (1)

Country Link
GB (1) GB2131971B (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0295825A1 (en) * 1987-06-15 1988-12-21 AT&T Corp. Method of achieving improved radial alignment in an optical package
GB2208944A (en) * 1987-08-19 1989-04-19 Stc Plc Fibre tailed welded optoelectronic transducer
US4826276A (en) * 1987-07-17 1989-05-02 E. I. Du Pont De Nemours And Company Optical fiber feedthrough assembly having a rigidizing arrangement therein
FR2623297A1 (en) * 1987-11-13 1989-05-19 Cit Alcatel COUPLING DEVICE BETWEEN AN OPTICAL FIBER AND AN OPTOELECTRONIC COMPONENT
US4844581A (en) * 1985-04-23 1989-07-04 Stc Plc Optical transmission package
US5177806A (en) * 1986-12-05 1993-01-05 E. I. Du Pont De Nemours And Company Optical fiber feedthrough
US5222170A (en) * 1987-04-03 1993-06-22 Bt&D Technologies Ltd. Optical fiber device fabrication
US5570444A (en) * 1994-12-12 1996-10-29 Northern Telecom Limited Method of optically coupling optical fibres to injection lasers
US6791058B2 (en) 2001-04-25 2004-09-14 Newport Corporation Automatic laser weld machine for assembling photonic components
US6896421B2 (en) 2003-02-26 2005-05-24 Lockheed Martin Corporation Method and apparatus for assembly of an optoelectronic device with an optical connector
US6902329B2 (en) 2003-02-12 2005-06-07 Lockheed Martin Corporation Method and apparatus for the integration of parallel optical transceiver package
US8231098B2 (en) 2004-12-07 2012-07-31 Newport Corporation Methods and devices for active vibration damping of an optical structure

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6198580B1 (en) 1998-08-17 2001-03-06 Newport Corporation Gimballed optical mount
US6516130B1 (en) 1998-12-30 2003-02-04 Newport Corporation Clip that aligns a fiber optic cable with a laser diode within a fiber optic module
FR2790115B1 (en) 1999-02-23 2001-05-04 Micro Controle METHOD AND DEVICE FOR MOVING A MOBILE ON AN ELASTICALLY MOUNTED BASE
US6511035B1 (en) 1999-08-03 2003-01-28 Newport Corporation Active vibration isolation systems with nonlinear compensation to account for actuator saturation
US6655840B2 (en) 2001-02-13 2003-12-02 Newport Corporation Stiff cross roller bearing configuration
US6601524B2 (en) 2001-03-28 2003-08-05 Newport Corporation Translation table with a spring biased dovetail bearing
US6568666B2 (en) 2001-06-13 2003-05-27 Newport Corporation Method for providing high vertical damping to pneumatic isolators during large amplitude disturbances of isolated payload
US6619611B2 (en) 2001-07-02 2003-09-16 Newport Corporation Pneumatic vibration isolator utilizing an elastomeric element for isolation and attenuation of horizontal vibration

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1573245A (en) * 1976-03-18 1980-08-20 Western Electric Co Hermetic seal for optical fibre
EP0030108A1 (en) * 1979-12-03 1981-06-10 The Post Office Improvements in or relating to the coupling of dielectric optical waveguides
EP0030617A2 (en) * 1979-12-06 1981-06-24 Philips Kommunikations Industrie AG Adjustable connection between an optical fibre to be measured and an optical fibre coming out of a measuring instrument
GB2065918A (en) * 1979-12-17 1981-07-01 Western Electric Co Coupling optical device
GB2093631A (en) * 1981-02-19 1982-09-02 Kokusai Denshin Denwa Co Ltd Unitary mounting structure for semiconductor laser and optical fiber
EP0061378A1 (en) * 1981-03-17 1982-09-29 Thomson-Csf Method for the controlled modification of the geometric characteristics of the end of an optical monomode fibre, and the use in optical coupling

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1573245A (en) * 1976-03-18 1980-08-20 Western Electric Co Hermetic seal for optical fibre
EP0030108A1 (en) * 1979-12-03 1981-06-10 The Post Office Improvements in or relating to the coupling of dielectric optical waveguides
EP0030617A2 (en) * 1979-12-06 1981-06-24 Philips Kommunikations Industrie AG Adjustable connection between an optical fibre to be measured and an optical fibre coming out of a measuring instrument
GB2065918A (en) * 1979-12-17 1981-07-01 Western Electric Co Coupling optical device
GB2093631A (en) * 1981-02-19 1982-09-02 Kokusai Denshin Denwa Co Ltd Unitary mounting structure for semiconductor laser and optical fiber
EP0061378A1 (en) * 1981-03-17 1982-09-29 Thomson-Csf Method for the controlled modification of the geometric characteristics of the end of an optical monomode fibre, and the use in optical coupling

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4844581A (en) * 1985-04-23 1989-07-04 Stc Plc Optical transmission package
US5177806A (en) * 1986-12-05 1993-01-05 E. I. Du Pont De Nemours And Company Optical fiber feedthrough
US5222170A (en) * 1987-04-03 1993-06-22 Bt&D Technologies Ltd. Optical fiber device fabrication
EP0295825A1 (en) * 1987-06-15 1988-12-21 AT&T Corp. Method of achieving improved radial alignment in an optical package
US4826276A (en) * 1987-07-17 1989-05-02 E. I. Du Pont De Nemours And Company Optical fiber feedthrough assembly having a rigidizing arrangement therein
GB2208944B (en) * 1987-08-19 1991-12-18 Stc Plc Welded two-part fibre tailed optoelectronic transducer package
GB2208944A (en) * 1987-08-19 1989-04-19 Stc Plc Fibre tailed welded optoelectronic transducer
US4988159A (en) * 1987-08-19 1991-01-29 Stc Plc Fiber tailed optoelectronic transducer
EP0316697A1 (en) * 1987-11-13 1989-05-24 Alcatel Cit Coupling device for an optical fibre and optoelectronic element
AU613677B2 (en) * 1987-11-13 1991-08-08 Alcatel N.V. A coupling device between an optical fiber and an opto-electronic component
FR2623297A1 (en) * 1987-11-13 1989-05-19 Cit Alcatel COUPLING DEVICE BETWEEN AN OPTICAL FIBER AND AN OPTOELECTRONIC COMPONENT
US5570444A (en) * 1994-12-12 1996-10-29 Northern Telecom Limited Method of optically coupling optical fibres to injection lasers
US6791058B2 (en) 2001-04-25 2004-09-14 Newport Corporation Automatic laser weld machine for assembling photonic components
US6902329B2 (en) 2003-02-12 2005-06-07 Lockheed Martin Corporation Method and apparatus for the integration of parallel optical transceiver package
US6896421B2 (en) 2003-02-26 2005-05-24 Lockheed Martin Corporation Method and apparatus for assembly of an optoelectronic device with an optical connector
US8231098B2 (en) 2004-12-07 2012-07-31 Newport Corporation Methods and devices for active vibration damping of an optical structure
US8651447B2 (en) 2004-12-07 2014-02-18 Newport Corporation Methods and devices for active vibration damping of an optical structure

Also Published As

Publication number Publication date
GB2131971B (en) 1986-12-10

Similar Documents

Publication Publication Date Title
GB2131971A (en) Positioning an optical fibre relative to an opto-electronic device
EP0304182B1 (en) Fibre tailed opto-electronic transducer
US4548466A (en) Optical fibre coupling assemblies
US4623220A (en) Laser to fiber connection
US6688783B2 (en) Method of fabricating an optical module including a lens attached to a platform of the optical module
KR100468130B1 (en) An optoelectronic assembly and method for fabricating the same
US6087621A (en) Method for laser hammering a multi-channel optoelectronic device module
JPS59109017A (en) Centered array for electrooptical device
JPH0792356A (en) Package for up-taper type single-mode optical fiber for optoelectronic part
US6786652B2 (en) Process for fabricating a photonics package and for aligning an optical fiber with a photodetector surface during fabrication of such a package
KR910009140B1 (en) Apparatus for manufacturing an optical transmission module
SU1373332A3 (en) Optronic module
JPH085876A (en) Module for light transmission and lens holder member used for the same
GB2229856A (en) Electro-optic transducer and sheet-metal microlens holder
JP3907051B2 (en) Optical module and manufacturing method thereof
JP2006064885A (en) Optical module and its manufacturing method
US6603093B2 (en) Method for alignment of optical components using laser welding
US6435735B1 (en) Assembling optical components
US6846113B2 (en) Packaging for high power pump laser modules
US7194182B2 (en) Methods and apparatuses using a fiber-flexure induction soldering station
Enochs A packaging technique to achieve stable single-mode fiber to laser alignment
JPS6365411A (en) Fixing method for lens
KR100226444B1 (en) Beam centering system and beam centering method of semiconductor laser module
JP2786325B2 (en) Optical semiconductor module
JP2936777B2 (en) Optical device module assembly equipment

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee