Optical True Time Delay Devices Based On Planar Polymer Waveguide

The use of polymer materials to fabricate long planar delay line devices is anoutstanding innovation in this thesis, and there is no related reports about the practicalproducts . The application of the polymeric optical waveguide devices and theintegration of functional modules are considered as efficient ways to achievehigh-performance and low-cost. Polymeric optical waveguide material has excellentfilm-forming property, excellent processability and excellent substrate compatibility.Especially in recent years, with the breakthrough in the optical loss, refractive indexcontrol, thermal stability, as well as the large-size three-dimensional photonicintegration, polymer shows many great advantages. In this thesis we introduced apolymer to fabricate waveguide optical true time delay line devices, and its keyparameters are as follows: The optical transmission loss is less than 0.3dB/cm. Therefractive index is between 1.450 and 1.580. The birefringence is less than 10~4.The5% weight loss temperature is higher than 300°C.The process of spin coating, photoresist coating, photolithography and reactive ionetching are all essential factors to fabricate high-quality optical waveguide devices. Inthis thesis, a cross-linkable negative photoresist (SU-8) as core material and anoptically UV curable epoxy (UV15) as cladding material are used for the design andfabrication of single-mode polymeric bend waveguides. In order to optimize theperformance of the devices, the insertion loss of the bend waveguides includingleaking loss, bend loss and birefringence loss are discussed. The direct UVphotolithography technique can provide a simple, rapid, and controllable process forfabricating optical integrated circuits (OICS). By the technology, single-mode60°polymer bend waveguides were successfully fabricated, the properties of thewaveguide profile were shown, the optical near-fields images were measured at 1550nm wavelength. At the same time, UV curing polymer material, ZPU was introduced tofabricate waveguide delay line devices. Until now, using this material ,we design asingle-mode low loss 60°polymer bend waveguides. The properties of the waveguideprofile were shown, the optical near-fields images were measured at 1550 nm wavelength. The experiments establish a good foundation for the future research ofthe fabrication of the OTTD devices.A unique spatial arrangement of spiral manner and an effective and accurate toolBPM are used to design the OTTD devices. Simulations of the Y branch, bending loss,S-bend, and the internal connections offest are listed. We have fabricated amulti-layer square waveguide. The structure of the device parameters were optimized.We analized the loss of the device, the optical power distribution of output channelsand accurately calculate the polymer / Si optical delay line waveguide mode, theeffective refractive index, bending radius, the length difference of adjacentwaveguides (optical path difference) and the deflection angle of the bend waveguide .Rely on these data, we have designed a mask. Some parameters can be achieved: The8 elements in real-time extension is 3bit(the working wavelength of 1550nm, FAinput and output). The adjacent channel time delay is 18.4ps. The 8 elements timedelay is 183.3ps.Arrayed-waveguide coupling technology and test technology are the key factors toimprove the transport efficiency, reduce device insertion loss, improve the stability.Generally seaking, silicon is not easy to get a excellent cleavage profile, so how tohandle the waveguide profile is also a key issue to be resolved. Based on theexperience of research on AWG, we have developed a systemic process which is alsosuitable to fabricate and test the optical true time delay line devices. We use asingle-sided polished Si substrate which is about 200μm thickness. After thefabrication of polymer optical waveguide, cleavage is implemented at roomtemperature or low temperature in order to improve the end-coupled quality of profile.Delay line device testing: using fiber which is connect with the laser as input, we takeadvantage of the infrared and microscopic imager to carry out observation.Since 60's of the 20th century, phased-array Antenna(PAA) has been introducedin the area of radar and communication. It is difficult for a conventional PAA toaccomplish wide instantaneous bandwidth under wide scan scope because of therestriction of aperture effect and the aperture traverse delay, which affects the systemabilities of resolution, detection and imaging of multi-target. The implementation ofoptical true time delay into PAA can obtain wide instantaneous bandwidth under widescan scope. Optical true time delay technology can take great advantages such asreducing bulk and weight, simplifing the structure, accommodating to adverseelectromagnetic environments, good stability of temperature, etc. Optical time delaytechnology mostly includes fiber time delay technology and integrated waveguidetime delay technology. This thesis studies and designs one new type of a planar In the 21st century, the U.S. Department of Defense has identified "photonics,opto-electronics" as one of the top ten national defense technologies in 2010. With thebreakthrough of the light modulators and other integrated optics technology, photonicstechnology is taking a more important role in practical engineering. China is still at theinitial stage of the research of the polymer materials and devices. Developing ahigh-performance planar optical waveguide devices will bring extensive influence insociety. Research and explore a new type of independent innovation ofhigh-performance polymer optical waveguide materials to resolve the primaryproblems of the polymer optical waveguide, is essential to the new generation ofhigh-speed, high-capacity all-optical network. At the same time, the direct and indirecteconomic benefits of polymer materials and photonics technology are obvious.