Research On Metal Cladding Defined Polymer Waveguide Grating Photonic Devices

In recent years,optical communication system is one of the most promising technologies because of its advantages over the traditional radio frequency system.Optical communication system also has the characteristics of broad-spectrum,high data rate,low delay,high security,low power consumption,etc.,so it has set off a wave of research in the scientific research.Among them,the resonant waveguide grating plays an important role in optical communication,and the transmitted signal can be located in the broad band from ultraviolet to microwave frequency.By using the characteristics of waveguide coupling,filtering and focusing,resonant waveguide grating can be used in biosensors,mode selectors and narrow band filters in the core component of lasers.In this paper,the self-synthesized organic-inorganic hybrid PMMA?polymethyl methacrylate?material?KH560??-?2,3-epoxypropoxy?propytrimethoxysilane??KH570??-?2,3-epoxypropoxy?propytrimethoxysilane??FBPA-PC EP?fluorinated epoxy-terminated polycarbonates?/FSU-8?fluorinated epoxy resin?and other polymer materials were utilized to fabricate grating photon devices,and the metal cladding structure aimed to simplify the fabrication process.Our fabricated devices using these principles improved the temperature sensitivity of photon devices,realized the function of dispersion compensation,suppressed side modes and achieved the function of periodic filtering.The main innovative works of this paper are as follows:1.A kind of organic-inorganic copolymerized SiO₂-TiO₂ network material was applied in this work.The metal cladding defined structure was used to form the thermo-optic long period grating.The temperature sensitivity of the filter was 3.5nm/°C which was about 1.75 times of that of metal grating which has been reported.The rise and fall times of the applied voltage switch were 1.1 ms and 1.2 ms,respectively.The previous reported metal grating had the rise and fall times of 19 ms and 11 ms,respectively.The measured temperature of T_g and T_d of the hybrid material were 135°C and 230°C,respectively.This organic-inorganic copolymerized material had a higher conversion temperature.For this metal cladding defined waveguide structure,only the core layer was needed to be spin coated and the electrode photolithography development was enough.The core layer development was not required,and the upper cladding was not required to be prepared,which meant it had the characteristics of simple process preparation.Combined with the characteristics of waveguide material and metal cladding structure,the device had higher temperature sensitivity and faster switching response.2.The fabrication of metal cladding defined chirped grating was realized by using organic-inorganic hybrid PMMA material.The metal cladding defined structure was used to form the thermo-optic chirped grating.When the 500-Hz applied square signal power was applied on the electrode,the rise and fall time of the switch were 467.0?s and 225.6?s,respectively.The compensation delay was 112 ps,and the measured group velocity dispersion was 2.1 ps/nm,which meant this device had a good disperation compension effect and it could solve the problem of dispersion and delay in optical network.This PMMA hybrid material had the characteristics of large thermo-optic effect,higher thermal stability and faster switch response.The T_g of this material was 153°C and the T_g of conventional PMMA material could only reach 100°C,which meant the thermal stability was obviously improved by the organic-inorganic copolymerization network.The reflection wavelength of the device was between 1530 and 1565 nm and the contrast was around 15 dB.The actual temperature sensitivity of the chirped grating was 0.2nm/°C and it could achieve the maximum reflection valley depth when the power was applied as 25 mW.This device had a higher temperature sensitivity and disperation compension.3.The low loss fluorinated photosensitive polymer material of fluorinated epoxy resin?FSU-8?and fluorinated epoxy polycarbonate?FBPA-PC EP?was utilized as the core layer.The metal cladding defined strucature was applied to fabricate the sampled apodized grating with high side-lobe supression ratio.The T_g and T_d of the device were 158.4°C and 302.9°C,respectively.The 3 dB bandwidth,wavelength spacing and side-lobe supression ratio were 4.8 nm,9.7 nm and 22.6 dB,respectively.The side-lobe suppression ratio was much higher than that of conventional Bragg grating.The previous published apodization grating had a side-lobe suppression ratio of less than 20 dB in general.The fabricated device showed the relationship between power consumption and wavelength drift was 24.9mW/nm.The relationship between temperature change and wavelength drift was0.175 nm/°C.These results had an improvement with previous proposed devices,which had the value of 37.7 mW/nm and 0.16 nm/°C.The material had a low absorption loss at 1550 nm.When the content of FSU-8 changed from 10 mol%to75 mol%,its refractive index could change from 1.495 to 1.565 and it realized the dynamic adjustment of refractive index.The T_g and T_d of the material were 158.4°C and 302.9°C,respectively.The device utilized the method of ridge dislocation to achieve apodization,which avoided the FP cavity effect caused by the traditional method of changing the width of ridge.This device achieved the combination of periodic filtering,broadband filtering,high sidelobe suppression and other functions.