New Host-Guest Polymeric System for Thermal Stability Enhancement of Electro Optic Effect
- PDF / 270,886 Bytes
- 6 Pages / 595 x 842 pts (A4) Page_size
- 92 Downloads / 160 Views
P9.25.1
NEW HOST-GUEST POLYMERIC SYSTEM FOR THERMAL STABILITY ENHANCEMENT OF ELECTRO OPTIC EFFECT
` Seung Koo Park, Jung Yun Do, Jung-Jin Ju, Suntak Park, and Myung-Hyun Lee Wideband Photonic Device Team, ETRI, 161 Kajong-Dong, Yusong-Gu, Taejon 305-350, Korea
ABSTRACT A new host-guest electro optic (EO) polymer, in which a chromophore can be reacted with the polymer main chain during poling to give the corresponding side-chain EO polymer, has been prepared for improving EO effect and its thermal stability. Polyisoimide (PII) synthesized from 2, 2-bis (4-aminophenyl) hexafluoropropane and oxydiphthalic anhydride and Disperse Red 1 (DR1) were used as a host and a guest, respectively. A model compound reaction and Infrared spectra of the host-guest film after annealing at various temperatures show that the reaction between the isoimide groups in PII and the hydroxyl groups in DR1 occurs around 140 oC. The glass transition temperatures of the resulting EO polyamic aicd ester-imide copolymer with 0, 10, 20 and 30 wt. % of chromophore concentration were 275, 219, 160, and 124 oC, respectively. The EO coefficient obtained at a wavelength of 1.55 µm was 5.3 and 10.5 pm/V from the EO polymer film with 20 and 30 wt. % DR1. The EO signals exhibited only a slight decay at high temperature due to the chemical reaction between the host and guest during poling.
INTRODUCTION Numerous EO polymers have been developed for practical applications of highspeed polymeric EO devices for around two decades. First of all, large EO coefficients (r33) and their stability are indispensable for such a realization of the high- speed devices. The high EO effect can be more effectively obtained from a host-guest polymer system than a side-chain, cross-linked, and main-chain polymer systems [1-3]. However, the thermal stability of EO effect of the host-guest system is not good enough for a practical device process, particularly in electrode patterning because photo resist work for micro patterning generally carried out around 100 oC [4, 5]. The side-chain and the crosslinked polymer system offer the promise of great long-term stability. However, this cross-linked polymer as a waveguide material is more difficult to manufacture, since the crosslinking reaction generally undergo during poling or just after poling [6]. Therefore, a changeable host-guest polymer system to the corresponding side-chain one during or after poling might be the best EO polymer system in consideration of the polling efficiency, the thermal stability of EO effect, and the waveguide fabrication. In order to obtain the high poling efficiency and to improve the decay of EO properties of the host-guest polymer system, we have tried to react a guest chromophore to a host polymer during poling. PII synthesized from 2, 2-bis (4-aminophenyl) hexafluoropropane (6F) and oxydiphthalic anhydride (ODPA) and DR1 were used as a host and a guest, respectively. The isoimide groups have been known to be sensitive to a
Downloaded from https://www.cambridge.org/core. Teachers College Librar
Data Loading...
