광굴절률제어.광기능고분자.광연결소자.광스위치.홀로그라피.Photo-induced refractive index control.photopolymer.optical connector.optical switch.holography.
초록▼
$/circ$폴리머소재 -광굴절률 제어소재 개발 (광유도 굴절률 제어 0.001이상, 도파소재1.51-1.59), UV/가시광영역의 광을 이용한 굴절률 제어가 가능한 소재 제법 확보, 박막 제조법, 굴절률 제어 특성 및 소자 제작 관련 기술 축적. -저손실 광경화성 투광소재 제조법 개발 (광손실 0.3dB/cm이하 @ 1550nm) -532nm 감광성 포토폴리머 개발 (회절효율 60% 이상) $/circ$폴리머 광연결 소자 제작 기술 개발: 폴리머 소재를 이용한 광연
$/circ$폴리머소재 -광굴절률 제어소재 개발 (광유도 굴절률 제어 0.001이상, 도파소재1.51-1.59), UV/가시광영역의 광을 이용한 굴절률 제어가 가능한 소재 제법 확보, 박막 제조법, 굴절률 제어 특성 및 소자 제작 관련 기술 축적. -저손실 광경화성 투광소재 제조법 개발 (광손실 0.3dB/cm이하 @ 1550nm) -532nm 감광성 포토폴리머 개발 (회절효율 60% 이상) $/circ$폴리머 광연결 소자 제작 기술 개발: 폴리머 소재를 이용한 광연결기 연구, 수동 광도파롤 소자 공정기술 개선, 도파손실 감소를 위한 기술력확보, know-how확보 (광분할기의 분배 균일도 1dB 이내, 광스위치의 누화특성 -20dB이하, 파장 가변 필터의 bandwidth 1nm이하 달성) -초단거리 광연결용 광도파로의 성능 향상(도파손실<0.4dB/cm @ 850nm), 광파워 분할기 제작 (출력 균일도 < 1dB): 기술이전, 논문 발표 -상품화가 가능한 정도의 quality를 가진 광소자(상온에서 100 시간 이상 작동)와 광도파로(자체손실 1dB/cm, external loss 10dB/cm 미만)를 개발 $/circ$광폴리머 소재를 이용한 다중 홀로그램 저장 기술 개발: 다중홀로그램 저장 (폴리머의 회전 다중화와 각다중화의 혼합: 독립적인 두 각의 step을 여러 가지로 변화시킨 결과 910개의 홀로그램을 한 곳에 저장함 (0.85mJ/cm2 기록광량)) $/circ$완전광 스위치 및 모듈레이터 모델 소자 제작, 고온, 저손실 수동광도파로 소자 제작, 특성 평가
Abstract▼
1)Preparation of polymers having low optical loss high refractive index change upon light exposure. We have accumulated synthetic skills for polymers doped or chemically bound with photoisomerizable chromophores. Synthetic methods for stable monomers and polymers have been established. Particular
1)Preparation of polymers having low optical loss high refractive index change upon light exposure. We have accumulated synthetic skills for polymers doped or chemically bound with photoisomerizable chromophores. Synthetic methods for stable monomers and polymers have been established. Particularly important was the development of photocurable fluorinated solutions. The solutions could be easily spin-coated onto silicon substrates and form highly transparent films under irradiation with UV light within 2 min. The result films showed very low optical loss (0.35 dB/cm) plus low birefringency (n=0.001) upon polymerization. polymer films having high refractive index change upon light exposure was prepared using the photocurable fluorinated solutions and photoisomerizable choromophore. The resultant films containg 10wt% of photoisomerizable choromophore showed photo induced refrctive index change of 0.002 by Vis and UV light. 2)Preparation of photopolymers We develop photopolymers, techniques for film preparation, instrumental set up and evaluation method for holographic recording. Finally we attempt to apply these newly developed photochromic polymers to holographic recording media. photopolymer film was prepared by doping the aromatic acrylate into a transparent po;ymeric binder or sol-gel process using organically modified alkoxy silanes. In particular, sol-gel process using organically modified alkoxy solanes an d an aromayi methacrylate (AMA) gave an increased refractive index change upon visible light excitation. Furthermore, photopolymer films having visible light sensivity could be fabricated in thickness up to ~1 millimeter. The photopolymerization was monitored by interfering two collimated plane wave beams of 532 nm. The original letter image with rectangular pixel was completely reconstructed in the photopolymer film with high resolution. 3)Multiplexed hologram storage in photopo;ymers We studied 100$\mum DuPont Photopolymer(HRF-150-100) for characteristics of hologram formation at 514nm with various grating spacings and light intensities as well as shrinkage ratios with various incdent angles. To combine rotational and angular multiplexings, we used two different rotational multiplexing schemes by rotation of photopolymer and regerence bea. We also performed shoft-retational multiplexing with rotation of reference beam. 4)Development of rewritable holographic recording film Photochromic polymer films for rewritable holographic recording media was prepared by using acetyl substituded diarylethene (DAMBTF6) and fluorinnated acrylate matrix. Photochromic films of 200micron thickness could be easily prepared by photo curing of the DAMBTF6 mixture in the presence of a photo initiator. The resyltant transparent films showed color change from pale yellow to a red by switching light sourve from visible (532nm) to an ultraviolet (365nm). Reversible refractive index change could be attatined from the polymeric film using ultraviolet and visible light sources. Holographic recording was performed the photochromic films by interfering two collimated plane wave beams. The records were completely erased ypon excitation with a visible or ultraviolet light, and the film was rewrtable eithder by 532nm laser or by 325 nm laser. Recording and erasing wad possible within 2 sec. Images were recorded onto a pixelated spatial light modulator (SLM) with rectangular pixel apertures and reconstructed on the photochromic films to show recovery of the original images with high resolution. 5)Polymer device (1)Development of molding process with a PDMS mold polymeric large-core(47$\mu$m x 41$\mu$m) optical waveguides for optical interconnection have been fabricated by using a molding process with a polydimethylsiloxane(PDMS) mold. For low-cost low-loss large-core waveguides, our newly developed thicke-photoresist patterning process is used for a master fabrication. also a low-loss thermocurable polymer, perfluorocyclobutane(PFCB), is used in fabricated by using the transfer molding process with a PDMS mold. By using this simple process and our newly developed UV curable materials (EFIRON WR seris), large core size (45$\mu$m x 45$\mu$m) multimode wveudes for very short-distance optical interconnection applications are easily prepared. Resulting waveguides exhibit very smooth surface profile and square cross section of core dimension. The propagation loss of faricated waveguide os measured to 0.2dB/cm at 850nm. (3)Fabrication of multimode waveguide devices for short-distance optical interconnection Large-core (1000$\mu$m x 1000$\mu$m) multimode optical waveguide device for a short-distance optical interconnection are fabricated by a molding process with a PDMS mold. The master is patterned by using Su-8 thick-photoresist developed for micro-electromechanical systems(MEMS) fabrication. The PDMS mold is used to replicate the waveguide is about 0.5dB/cm at the wavelength of 650nm. Based in these waveguides, two types of the power splitter have been fabricated; one is T-shaped and the other Y-shaped. The T-shaped splitter has a structural excess loss of 1.5dB and its split ratio os 1 : 0.96. The Y-shaped splitter has a structual excess loss of 0.3dB and its split ratio is 1 : 1.04. (4)Fabrication of a multimode waveguide with a 45 degree mirror for optical interconnection Multimode waveguide with a 45 degree mirror is fabricated by a molding process with a PDMS mold. A thick photoresist AZ9260 is used in patterning the master. The waveguide has dimensions of 50$\mu$m x 50$\mu$m since it is used for very short-distance optical interconnection like the interconnection on a board. For the replication to polymer, WG-25 and NOA73, UV-curable epoxy are used ad core materials. The propagation lossed are measured to be 0.9dB/cm for WG-25 and 0.4dB/cm for NOA73 at the wavelength of 850nm. A method of fabricating 45 degree mirrors at the end of these waveguides by titling the sample and illuminating UV is proposed. The measured loss of a mirror is about 0.9dB. (5)Fabrication of a filter using the multimode waveguide fabrication process We have demonstrated the feasibility of the process fabricating a single-mode waveguide and a multimode waveguide aligned vertically in the same substrate. Using this process, we have proposed and deminstrated a filter that drops optical signal propagpating in a single-mode wavesuide to a multimode wavewuide in the specifc wavelength interval by a long-period grating. The fabrication process of this filter consists of conventional fabrivation of the single-mode waveguide and fabrication of the multimode waveguide with a large cross-section area, e. g. 50$\mu$m x 50$\mu$m by the molding method with a PDMS mold. We have used thermo-curable polymers PFCB and BCB as the cladding and the core materials, respectively. For the multimode waveguide core polymer, we have used the UV-curable epoxy, NOA61. the center wavelength of the fabricated filter with a grating period of 315.9$\mu$m is 1537.7nm. The grating-interaction length is 11mm and the maximum attenuation at the center wavelength is 17.8dB.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.