The Research On Characteristic Of Guest-host EO Material

Human society is entering into an information age powered by rapidlyevolving technologies in areas of microelectronics, optoelectronics,computing and communications. For several decades, a number of newmaterials and corresponding devices have been driving force for thisprocess including semiconductor laser, efficient fiber optic transmissionlines and optic fiber amplifiers, new and efficient optical detectors and lightmodulators, and etc. However, due to the rapid increase of information,continuous requests have been made for the increase of speed, theenlargement of capacity and the decrease of cost of communications, sometraditional communication technologies and devices could not fulfill thedemands of applications.Today most commercial EO materials are inorganic or semiconductormaterials like LiNbO3 and GaAs.It is already comparatively ripe to develop,but the market captured is very limited. This relatively mainly because ofthe high dielectric constant of material , half voltage often not low, it isdetermined that it is difficult for them to realize the modulation of the EO inhigh-speed and large capacity , this is one of the main limitations ofphoto-communication technical development too, and being material fragile,it is also very difficult to grow on other bottom thing(such as silicon chip),making the cost of manufacture of the wave guide device high, the price isvery expensive . The photo-communication of new generation shouldbreaking through these limitations, the EO material of new-type must bedeveloped high efficiency , respond fast technically.the EO polymer has enormous prospect potentially in this respect, it has alot of excellent performance , such as EO coefficient being big, the EOactivation is high, response speed soon, little chromatic dispersion ofrefracting, low dielectric constant, easy to integrate etc., cause people'sextensive concern , develop vigorously in recent years. the EO polymeraccording to structure characteristic can divide into 4 kinds roughly: mixtype, side chain type , main chain type and cross link type . Host -Guesttype is the most simple one, it add chromophore into host group throughsolvent dissolve altogether. This kind of method is prepared simply, the costis cheap, the EO coefficient of is relatively great; But by the two restrictionof dissolving each other, the density of mixing of adding chromophore tothe group can't be very high, this restrain from the material EO coefficientfurther to raise , and its stability can't make people satisfied. So people's keymajority of research concentrates on the material of other several kinds. Ithas been reported that cross linked organic molecule tree has beensynthesizeed whose EO coefficient up to one hundred pm/v, and havelong-term stabilities under 80 ℃. Though compared with inorganic andsemiconductor material , cross linked polymer material's cost drop to someextent, but it is complicated to prepare, the cost is still high .Can we synthesize a kind of material with simple method , with cheapcost and with superior performance? The development of sol-geltechnology has offered possibility for this.Recently,it was reported thatpoled fused silica glass containing no dye had stable nonlinearity,but thevalue of SHG was very small.To increase the nonlinearity,nonlinearmolecules must be doped and oriented.The sol-gel method has beendeveloped to synthesize amorphous silica glass or other inorganic oxideglass at low temperature,stating from solutions containing alkoxides.Henceorganic dyes soluble in the starting solution can be doped in the glass.Thisfilm containing dye is baked and poled ,that is,the dye molecules aredispersed in numerous pores of the oxide matrix.Hence,this is not aglass,but a complex amorphous film containing dye.This complex file hasrelatively high transparency and thus is promising for waveguide poticaldevices.The main contents are following:1. The research history and current situation about poled polymer electro-opticmaterials were reviewed. The advantages of organic electro-optic materials overinorganic materials were pointed out. All kinds of applications of the organicelectro-optic materials in the field of optoelectronics were discussed. The origin of theelectro-optic effect of organic electro-optic materials was analyzed from the chemistryconfiguration of the materials.2. It is discussed that the electric field pole technological method , thecharacteristic and question that should be paid attention to, have recommended byusing simple reflecting method to measure the EO coefficient briefly. we habeprepared the polymer material of PMMA/DR-1 on this basis, through adjusting suchparameters as voltage , electric current , time ,etc., have found the best polarizationcondition , and has tested its EO coefficient , characteristic of decaying,etc. Throughmonitoring the polarization electric current and voltage in the course , making thepolymer membrane in the best condition of polarising all the time, we havesuccessfully solved the contact poling problem.3. We have reviewed the developing history of the sol-gel method , has pointed...