Photostability of high μβ electro-optic chromophores at 1550 nm

We present the photostability results of seven novel electro-optic chromophores made to be used in highspeed fiber optic signal modulators. We measured the photobleaching rate of the chromophores at room temperature by using a fiber optic pump-probe technique. Thin polymer film guest-host samples were deposited on the end of SMF-28 fiber pigtails and bleached by using 100 mW of 1550 nm radiation as the pump. The bleaching rate was measured by monitoring the main absorption band of the chromophores by using a 660 nm probe beam that was multiplexed into the fiber pigtail. The relative photostability was reported as a figure of merit which is proportional to the I/e bleaching lifetime of the chromophore. We found the bleaching rate to increase linearly with incident 1550 nm power at the end of the single-mode fiber up to at least 100 mW. Our results show that the photobleaching rate is reduced dramatically when the test is conducted in an inert atmosphere. We also show that the presence of the singlet oxygen quencher DABCO can be used to increase the lifetime of the chromophore. The effect that chromophore structure and polymer host type have on photostability are also discussed.