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A novel, compact, and tunable lithium niobate (LN) planar waveguide loop structure composed of two Y junction reflectors is proposed for optical and radio frequency signal processing applications. The preliminary device shows a high quality factor of 6.5 x 10(4), due to the low propagation loss of the titanium-diffused LN waveguide. The tunability of the loop by electric field is estimated.

Crosstalk in a balanced bridge interferometric-type optical switch is highly suppressed by using Mach-Zehnder (MZ) structures as intensity trimmers. An imbalance in optical power is caused by deviations from the ideal dividing ratio of directional couplers in the switch, which causes an increase in the crosstalk. This imbalance was compensated for by adjusting the transmittances of the nested MZ structures. A crosstalk of less than 55 dB has been achieved even for alternating voltage signals. It is also shown that the crosstalk reduction is possible for a control voltage signal of more than 10 GHz, which is based on double-sideband suppressed-carrier modulation spectra measurement results. [ABSTRACT FROM PUBLISHER]

We demonstrated reciprocating optical modulation using erbium-doped LiNbO3 crystal for high-order sideband generation and selective amplification. A Ti-diffused waveguide, formed on the crystal, had a gain of 2.1 dB/cm for 1531.4-nm signal light pumped at 1480 nm with a pump power of 200 mW/port. A sideband component of 40 GHz was successfully enhanced and a gain of 12 dB was realized. [ABSTRACT FROM PUBLISHER]

A resonant-type optical modulator array connected with antennas can effectively convert a micro/millimeter-wave to a light wave for the uplink of a radio-on-fiber system. We demonstrated the operation of an array that contained four modulators using power simultaneously received by microstrip antennas connected to each modulator. We confirmed that the optical phase change induced by the received power was proportional to the number of connected antennas [ABSTRACT FROM PUBLISHER]