CN1410788A

CN1410788A - Double cladded plastic amplifier optical fibre

Info

Publication number: CN1410788A
Application number: CN 02142342
Authority: CN
Inventors: 于荣金; 李炳新
Original assignee: Yanshan University
Current assignee: Yanshan University
Priority date: 2002-12-27
Filing date: 2002-12-27
Publication date: 2003-04-16
Anticipated expiration: 2022-12-27
Also published as: CN1219226C

Abstract

The dopant with high refractive index for the optical fiber core is triphenyl phosphite, and the inner packet-layer and outer packet-layer are coated on the external surface of the optical fiber core. The procedure for preparing the optical fiber is as follows. The purified MMA monomer and the chain transfer agent etc. are put into circular (or noncircular) glass tube. The glass tube containing the above said mixed liquid is put into the temperature control furnace with being rotated at certain speed so as to form the inner packet-layer tube of the PMMA optical fiber. With the MMA solution containing rhodamine B etc. being put into, the tube is put into the furnace so as to form the optical fiber preformrod. The product is made after drawing the preformrod and coating it by the outer packet-layer with low refractive index.

Description

Double clad plastics amplifier optical fiber

The present invention relates to a kind of photoelectron material and devices field.

At present, the plastics telecommunication optical fiber has obtained fine development, is expected to be used for LAN (Local Area Network), CATV (cable television) and user network etc., substitutes copper cabling.Application and function expansion that the plastic optical fiber amplifier can be plastic optical fiber network provide important support.Japan keio university utilizes mixes the plastic optical fiber amplifier of rhodamine B, and maximum gain has reached 37dB; The plastic optical fiber amplifier of Australia's development has also obtained the gain of 23dB.But find in the research that in mixing the polymer optical fiber of rhodamine B, the pulse pump power of 532nm wavelength the bleaching [A.Tagaya, etal., Appl.Opt., 34 (6) 988～992,1995] of dyestuff occurs during greater than 800W in the porch of optical fiber; In continuous power is under the 514nm Ar laser radiation of 4.3mw (power that enters optical fiber is 1.3mw), fluorescence drop by half after about 10 hours [G.D.Peng, etal., J.Lightwave Technol., 14 (10) 2215～2223,1996].Therefore, the heat of avoiding mixing the dyestuff plastic optical fiber degenerate (thermoinduction bleaching) be the key issue that plastic optical fiber amplifier practicability institute must solution.

The object of the present invention is to provide a kind of double clad structural plastic amplifier optical fiber, this double clad structure is because the inner cladding diameter can reach 1000 μ m, core diameter 30 μ m, 60 μ m and 250 μ m than reported in literature are much bigger, under identical pump power, pump light intensities can drop to 1/1111,1/278 or 1/16 respectively on the unit cross section.This heat that just is very beneficial for avoiding mixing the dyestuff plastic optical fiber is degenerated, and perhaps can further improve pump power, obtains bigger gain.

This double clad plastics amplifier optical fiber, comprise fiber cores 1, inner cladding 2 and surrounding layer 3 compositions, it is characterized in that: the high index of refraction adulterant of the fiber cores 1 of this optical fiber is a triphenyl phosphite, its outside surface applies one deck inner cladding 2 and one deck surrounding layer 3, the cross section of inner cladding 2 is round section or non-circular symmetrical section, and the cross section of surrounding layer 3 is circular; The cross section of the section ratio fiber cores 1 of inner cladding 2 is big 10～1000 times, and symmetry can also can non-ly be justified with one heart with inner cladding 2 off-centre in the position of fiber cores 1; Its manufacturing process is: a. stirs 0.2% chain-transferring agent n-butyl mercaptan of 0.1～0.5% chain initiator benzoyl peroxide of the MMA monomer of purifying, MMA weight and MMA weight, and 90 ℃ of about 20 minutes of heating down, cool to room temperature promptly becomes prepolymer.The material that pre-polymerization is good is put into the quartz glass tube of circular or non-circular symmetrical section, two ends are airtight, select the sleeve of the status requirement that satisfies fiber cores 1 for use, to put into the hollow tubular of 3000～5000 rev/mins of high speed centrifugation revolutions of rotating speed polyplant with the glass tube of sleeve then, carry out polymerization forming, when polymerization temperature was 80 ℃, polymerization time was 15 hours, had finished the making of PMMA inner cladding 2 by this step; B. the feed liquid of 1% high polar reagent dimethyl sulfoxide of 0.2% chain-transferring agent n-butyl mercaptan of 0.1～0.5% chain initiator benzoyl peroxide of the rhodamine B of MMA and 10～100PPm, MMA weight, MMA weight, MMA weight and high index of refraction adulterant triphenyl phosphite is packed into after pre-polymerization in PMMA inner cladding 2 pipes, 60 ℃ of de-bubbled 10 minutes, seal cladding, put into the polymeric kettle polymerization then; The controlled variable of polymerization process was a temperature and time, finished polymerization through 70 ℃, 2 hours → 90 ℃, 12 hours → 120 ℃, 24 hours; Polyreaction is from the interface (interface gel polymerization) between inner cladding 2 and the core material, and refractive index progressively reduces to circumference in the middle of the core district, forms the prefabricated rods that graded index distributes; C. prefabricated rods is under 170 ℃～200 ℃ temperature and pulling force, with certain rate of extension preform bar stretching is become the optical fiber shape, in the drawing process, fine footpath is by the photoelectric monitoring system regulation, is fiber cores 1-inner cladding 2 structures of drawing optic fibre shape that 1.38 organic siliconresin applies groove and forms surrounding layer 3 by refractive index, solidify through the about 70 ℃ of drying channels of temperature, receive silk, obtain the optical fiber that the graded refractive index plastic optical-fiber amplifier is used through wire wrapping disk.

In order to improve absorption efficiency, generally be to make fiber cores 1 depart from positive center (being that fibre core and inner cladding are non-concentric circles), or make some variation of shape (non-circle symmetry) of inner cladding 2 pump light.

Drawings and Examples

The structural representation of the double clad plastic optical fiber that Fig. 1 fiber cores and inner cladding are concentric

The structural representation of the double clad plastic optical fiber of Fig. 2 fiber cores and inner cladding off-centre

Fig. 3 inner cladding cross section is the structural representation of the double clad plastic optical fiber of rectangle

Fig. 4 inner cladding cross section is the structural representation of foursquare double clad plastic optical fiber

Fig. 5 inner cladding cross section is the structural representation of quincuncial double clad plastic optical fiber

Accompanying drawing 2 is an embodiment (see figure 2) disclosed by the invention, and 1 is the plastic optical fiber core, and 2 is inner cladding, and 3 is surrounding layer.In the present embodiment, add a certain amount of chain initiator benzoyl peroxide (MMA weight 0.1～0.5%) and chain-transferring agent n-butyl mercaptan (MMA weight 0.2%) in MMA, stir, heated about 20 minutes down at 90 ℃, cool to room temperature promptly becomes prepolymer.The material that pre-polymerization is good is put into the quartz glass tube of φ 18mm, two ends are airtight, select for use and satisfy the sleeve that degree of eccentricity requires, will put into the hollow tubular of high speed centrifugation revolution (3000～5000 rev/mins of rotating speeds) polyplant with the glass tube of sleeve then, carry out polymerization forming.When polymerization temperature was 80 ℃, polymerization time was about 15 hours; When polymerization temperature was 70 ℃, polymerization time was about 20 hours.Finished the making of PMMA inner cladding 2 by this step.Again by the requirement of fiber cores, prepare burden: except that MMA, add 0.1～0.5% chain initiator benzoyl peroxide, the MMA weight of rhodamine B, the MMA weight of 10～100PPm 0.2% chain-transferring agent n-butyl mercaptan, an amount of (as MMA weight 1%) high polar reagent (dimethyl sulfoxide) and high index of refraction adulterant (triphenyl phosphite).Add dimethyl sulfoxide and be for improve the solubleness of rhodamine B in MMA, add triphenyl phosphite (refractive index is 1.588) be for the refractive index that makes core region greater than inner cladding.The above-mentioned feed liquid for preparing is packed into after pre-polymerization in the PMMA inner cladding pipe, and 60 ℃ of de-bubbled 10 minutes have been sealed cladding, put into the polymeric kettle polymerization then.The controlled variable of polymerization process is a temperature and time.Finished polymerization through 70 ℃, 2 hours → 90 ℃, 12 hours → 120 ℃, 24 hours.Polyreaction is from the interface (interface gel polymerization) between inner cladding and the core material; Refractive index progressively reduces to circumference in the middle of the core district, forms the prefabricated rods that graded index distributes.Prefabricated rods becomes the optical fiber shape with certain rate of extension with preform bar stretching under 170 ℃～200 ℃ temperature and pulling force.In the drawing process, fine footpath is by the photoelectric monitoring system regulation.The core of drawing optic fibre shape-inner cladding structure is applied groove by liquid (organic siliconresin, refractive index are 1.38), and drying passage (about 70 ℃ of temperature) solidifies.Receive silk through wire wrapping disk, obtain the optical fiber that the graded refractive index plastic optical-fiber amplifier is used.

By the present invention, to mixing 100PPm rhodamine B, inner cladding diameter is that 900 μ m, core diameter are that 250 μ m, eccentric throw are the long eccentric double clad plastic optical fiber of 70cm of 100 μ m, use the Nd:YAG frequency double laser, at 532 wavelength with the continuous power pumping of 25mw after 10 hours, do not have fluorescence intensity decline phenomenon, illustrate that this structure can well solve the thermal dye degenerate problem

Claims

1. double clad plastics amplifier optical fiber, comprise fiber cores (1), inner cladding (2) and surrounding layer (3) composition, it is characterized in that: the high index of refraction adulterant of the fiber cores of this optical fiber (1) is a triphenyl phosphite, its surface-coated one deck inner cladding (2) and one deck surrounding layer (3), the cross section of inner cladding (2) is round section or non-circular symmetrical section, and the cross section of surrounding layer (3) is circular; The cross section of the section ratio fiber cores (1) of inner cladding (2) is big 10～1000 times.

2. method of making the described double clad plastics of claim 1 amplifier optical fiber is characterized in that:

A. with 0.2% chain-transferring agent n-butyl mercaptan of 0.1～0.5% chain initiator benzoyl peroxide of the MMA monomer of purifying, MMA weight and MMA weight, stir, 90 ℃ of about 20 minutes of heating down, cool to room temperature promptly becomes prepolymer;

B. pre-polymerization is good material is put into the quartz glass tube of round section or non-circular symmetrical section, two ends are airtight, select the sleeve of the status requirement that satisfies fiber cores (1) for use, to put into the hollow tubular of 3000～5000 rev/mins of high speed centrifugation revolutions of rotating speed polyplant with the glass tube of sleeve then, carry out polymerization forming, when polymerization temperature was 80 ℃, polymerization time was 15 hours, had finished the making of PMMA inner cladding (2) by this step;

C. the feed liquid of 1% high polar reagent dimethyl sulfoxide of 0.2% chain-transferring agent n-butyl mercaptan of 0.1～0.5% chain initiator benzoyl peroxide of the rhodamine B of MMA monomer and 10～100PPm, MMA weight, MMA weight, MMA weight and high index of refraction adulterant triphenyl phosphite is packed into after pre-polymerization in PMMA inner cladding (2) pipe, 60 ℃ of de-bubbled 10 minutes, seal cladding, put into the polymeric kettle polymerization then; The controlled variable of polymerization process was a temperature and time, finished polymerization through 70 ℃, 2 hours → 90 ℃, 12 hours → 120 ℃, 24 hours; Polyreaction is from the interface (interface gel polymerization) between inner cladding (2) and the core material, and refractive index progressively reduces to circumference in the middle of the core district, forms the prefabricated rods that graded index distributes;

D. prefabricated rods is under 170 ℃～200 ℃ temperature and pulling force, with certain rate of extension preform bar stretching is become the optical fiber shape, in the drawing process, fine footpath is by the photoelectric monitoring system regulation, is the fiber cores of drawing optic fibre shape (1)-inner cladding (2) structure that 1.38 organic siliconresin applies groove and forms surrounding layer (3) by refractive index, solidify and wire wrapping disk receipts silk through the about 70 ℃ of drying channels of temperature, obtain the optical fiber that the graded refractive index plastic optical-fiber amplifier is used.

3. double clad plastics amplifier optical fiber according to claim 1 is characterized in that: the position of fiber cores (1) can and inner cladding (2) off-centre also can be non-the circle symmetry with one heart.