CN101561533A

CN101561533A - Ion exchange technical condition based on neodymium doped phosphate glass channeling optical waveguide

Info

Publication number: CN101561533A
Application number: CNA200910059416XA
Authority: CN
Inventors: 张晓霞; 周勇; 张金令; 刘永智
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2009-05-26
Filing date: 2009-05-26
Publication date: 2009-10-21

Abstract

The invention provides an ion exchange technical condition based on neodymium doped phosphate glass channeling optical waveguide, belongs to the technical field of optical communication, and relates to the technology of optical waveguide. In the technical condition, ion exchange molten salt is evenly mixed by mixed molten salt consisting of AgNO3 and KNO3 according to a molar concentration ratio of 9:10 after dehydration; and ion exchange time is to exchange for 25 minutes under a condition of 350 DEG C. The ion exchange condition prepares compositions and concentration of the exchange molten salt again aiming at the characteristics of a neodymium doped phosphate material, adopts high purity molten salt of AgNO3 and KNO3, properly improves the concentration of exchange ions, and shortens the exchange time so as to possibly reduce the influence of the molten salt on the surface of a substrate in an exchange process, thereby improving the quality of the optical waveguide.

Description

Ion exchange technique condition based on neodymium doped phosphate glass raceway groove optical waveguide

Technical field

Ion exchange technique condition based on neodymium doped phosphate glass raceway groove optical waveguide belongs to the optical communication technique field, relates to optical waveguide technique.

Background technology

Neodymium doped phosphate glass has good thermal stability and chemical stability under the high power operation condition, and the phonon energy of phosphate glass is moderate, to neodymium ion solubleness height, neodymium ion spectrum property therein is good, nonlinear factor is little, make neodymium doped phosphate glass become one of the widest laser glass medium of use, in laser fusion, medium and small Energy device, waveguide laser and optical-fibre communications, obtain important use.Optical waveguide laser and amplifier all are novel optical communication Laser Devices, have abroad reported optical waveguides amplifier and the laser instrument made of different process on various neodymium-doped laser materials in a large number, and domestic research in this field also is in the starting stage.But because they have many advantages that semiconductor laser and fiber amplifier commonly used, semi-conductor amplifier can not be compared, the replacement latter has been certainty in following optical communication and light are integrated.

Ion exchange technique has the advantages such as glass optical waveguide that technology is simple, easy to operate, with low cost, can make complexity, in optical communication, optical sensor and other fields that need handle and control light signal, obtained to use widely, become the preferred option of making glass optical waveguide.Ion-exchange process is made optical waveguide on glass substrate ultimate principle is: with the cation A that melts in the salt (or the metal film electrolysis forms)+carry out ion-exchange under given conditions with kation B+ in the glass.Cation A+enter after the glass surface to the glass internal divergence, forms cation A+diffusion layer under the effect of self concentration gradient.Because A+ has higher polarizability than B+, perhaps become fine and close more because of having the partial structurtes that littler ionic radius makes glass, thereby the refractive index of glass had bigger contribution, so the refractive index of diffusion layer increases than the refractive index of substrate glass, become waveguide core layer.It is low that the glass-based integrated optical device that adopts ion exchange technique to make has loss, is easy to the doped with high concentration rare earth ion, and with the optical characteristics coupling of optical fiber, coupling loss is little, and environmental stability is good, is easy to and characteristics such as other optoelectronic components are integrated.

In making the waveguide type optical device, often use and be to bury the type optical waveguide than what be easier to make.The type optical waveguide is buried in making, improves the symmetry of light wave guided mode field, is the key point that reduces the loss of fiber waveguide device.Can know that from the theoretical analysis of channel waveguide under the situation of operation wavelength and other parameter constant of waveguide, the guided mode number in the waveguide is proportional with the waveguide degree of depth.Consider that the primary goal that experimentizes is to make waveguide can lead to light, thereby if the probability of increase Success in Experiment just need be selected the process conditions that can increase the waveguide exchange degree of depth for use.

Summary of the invention

The technical problem to be solved in the present invention is exactly how to adopt the ion exchange technique under the specified conditions to make the channel-type optical waveguide on the neodymium doped phosphate glass material, and make based on this can the single mode operation, neodymium doped phosphate optical waveguide laser and optical waveguides amplifier that loss is low.

Concentration relationship (K according to contained ion in the neodymium doped phosphate glass material ⁺＞Na ⁺＞Li ⁺) and the coupled ion exchange theory in the glass materials refractive index situation of change that causes of various ion-exchanges, preparation is by AgNO ₃And KNO ₃Molar concentration rate is that salt is melted in the mixing of forming at 9: 100, and mixes after melting dehydration of salt.Adopt this component and concentration proportioning, coupled ion switching technology, the waveguide of easier formation channel-type.

Ion-exchange can be regarded the phase counterdiffusion between two or more ion as.Ion-exchange increases refractive index or reduces, due to following two factors.First factor is relevant with the atom size dimension of exchange ion.If use Li ⁺Replace Na ⁺Or K ⁺Such heavy ion, glass grid take place to burst around small ion to collapse, and produce quite intensive structure, have high refractive index; If use heavy ion to substitute small ion, grid expands, and produces sparsity structure, obtains lower refractive index.Second factor is to consider the electron displacement polarization rate.If use Tl ⁺, Cs ⁺, Ag ⁺, Rb ⁺Or K ⁺, the bigger ion of this electron displacement polarization rate has been replaced Na ⁺The less ion of this electron displacement polarization rate, refractive index will increase.At containing many K in the general neodymium doped phosphate glass material ⁺Secondly ion is Na ⁺And Li ⁺If use Ag in the exchange ⁺, K ⁺And Na ⁺, the ion-exchange of following complexity will take place so:

As shown in Figure 1.Adopt AgNO ₃And KNO ₃Mixing melt salt and carry out ion-exchange experiment, following ion-exchange will take place

As shown in Figure 2.According to the ion-exchange theory

Ion-exchange the refractive index of glass material is increased, thereby total exchange effect also can make the refractive index of exchange area increase, and then forms waveguide, as shown in Figure 3.

Considering that neodymium doped phosphate melts the component and the concentration proportioning of salt, according to the ion-exchange theory, is 25 minutes 350 ℃ of condition following swap times, exchanges out the waveguide of 1 pattern.Adopt short ion-exchange time, can reduce high temperature in the exchange process as much as possible, melt salt, reach of the influence of other factors, and then improve the quality of optical waveguide the substrate surface structure.

Influence the formation of single mode waveguide and the factor analysis of performance:

(1) melt the influence of salt quality: ion-exchange is used melts salt to be generally the analysis of purity about 99.8% pure, melts the impurity and the ion that contain other in the salt, and these impurity or ion might cause damage to substrate when carrying out ion-exchange with substrate.Adopt impure still less, the pure salt that melts of top grade that purity is higher carries out ion-exchange, the amount that not only exchanges rear impurity reduces, and the substrate surface quality after the exchange has also had very big improvement.

(2) melt dehydration of salt and mixing: pure AgNO ₃Character is more stable, preserves at the drying place of lucifuge and generally deliquescence can not take place.And KNO ₃Then have more intense water absorptivity, preserve although be put in dry place, deliquescence still can take place in it.The salt vacuum dehydration method is melted in employing, only to consumption deliquescent again KNO how ₃Dewater.Again with AgNO ₃Put into the KNO that is in happy and harmonious state after the dehydration ₃In, make it fully to merge a period of time, to reach mixed uniformly purpose.

Beneficial effect of the present invention:

1, makes AgNO ₃And KNO ₃Molar concentration rate is that salt is melted in 9: 100 high Ag concentration mixing, suitably improves exchange ion concentration, shortens ion-exchange time, reduces in the exchange process and melts the influence of other factors such as salt, high temperature to substrate, has improved the optical waveguide quality greatly.

2, at the neodymium doped phosphate properties of materials, the preparation exchange is adopted highly purified AgNO with the component and the concentration of melting salt again ₃And KNO ₃Melt salt, when improving exchange ion concentration, can shorten swap time, reduce the influence of melting the salt pair substrate surface in the exchange process as much as possible, thereby can exchange out high-quality optical waveguide.

3, control ion-exchange time makes to exchange out to have the more single mode waveguide of low transmission loss, and monomode optical waveguide amplifier or laser instrument have better performance.

Using value of the present invention: single mode neodymium doped phosphate glass optical waveguide laser and amplifier have a wide range of applications at high power array laser instrument and amplifier, high-speed wideband optical communication and military field.

Description of drawings

Figure 1A g ⁺, K ⁺And Na ⁺Mix and melt salt and glass substrate intermediate ion exchange synoptic diagram, wherein, 1 is silica crucible, and 2 for melting salt, and 3 is refractive index, and 4 is substrate.

Fig. 2 Ag ⁺And K ⁺Mix melt salt and neodymium doped phosphate glass material the ion-exchange synoptic diagram, wherein, 1 is silica crucible, 2 for melting salt, 3 is refractive index, 4 is substrate.

Fig. 3 channel waveguide manufacture craft synoptic diagram, 5 for removing the substrate of photoresist; 6 is the aluminium film; 7 is wave guide zone; 8 are ion-exchange; 9 for removing aluminium film formation waveguide.

Claims

1, based on the ion exchange technique condition of neodymium doped phosphate glass raceway groove optical waveguide, comprise that the used mixing of ion-exchange melts salt component, matched proportion density, and after melting the dehydration of salt processing, evenly mix, melt salt and carry out time in the ion exchange process with adopt mixing, it is characterized in that, mix and melt salt proportioning composition and concentration and swap time.

2, the ion exchange technique condition based on neodymium doped phosphate glass raceway groove optical waveguide according to claim 1 is characterized in that, it is silver nitrate (AgNO that the salt composition is melted in described mixing ₃) and potassium nitrate (KNO ₃).

According to claim 1,2 described ion exchange technique conditions, it is characterized in that 3, the pure salt that melts of top grade that the salt employing is impure still less, purity is higher is melted in described mixing based on neodymium doped phosphate glass raceway groove optical waveguide.

4, according to claim 1,2 described ion exchange technique conditions, it is characterized in that salt AgNO is melted in described mixing based on neodymium doped phosphate glass raceway groove optical waveguide ₃And KNO ₃With molar concentration rate is 9: 100 proportionings.

5, the ion exchange technique condition based on neodymium doped phosphate glass raceway groove optical waveguide according to claim 4 is characterized in that, described mixing is melted salt and must evenly be mixed through after melting salt vacuum dehydration method processed.

6, the ion exchange technique condition based on neodymium doped phosphate glass raceway groove optical waveguide according to claim 1 is characterized in that, described mixing is melted salt ion exchange temperature and accurately is controlled at about 350 ℃.

7, the ion exchange technique condition based on neodymium doped phosphate glass raceway groove optical waveguide according to claim 6 is characterized in that, described mixing is melted salt ion and accurately was controlled at 25 minutes swap time.