Optical add/drop multiplexers (OADMs) are finding their applications in future all-optical communication networks to link the network with local transmitters and receivers. A novel fully dynamic and reconfigurable OADM based on AOTF with low crosstalk is presented. The PMD compensation issue of AOTF is addressed as well.

In the paper, a weighted-coupling scheme of a SiO2 film-loaded Ti:LiNbO3 quasi-collinear integrated acousto-optic mode converter is reported, in which an angular offset between the acoustic and optical waveguides is introduced to implement an optimized Hamming weighted function for realization of ultralow sidelobe level. Acoustic wave guiding properties have been investigated for films such as SiO2, ZnO on LiNbO3 firstly. SiO2 film on LiNbO3 was selected as acoustic waveguide. With the mode analysis of the acoustic wave guide and the theory of coupling mode the limit of the width, weighted coupling coefficient and the characteristics of the conversion of acousto-optic modes are obtained. As the angle between acoustical and optical waveguides guides is 0.45ο, the worst sidelobe level is −16.8dB and the theoretical values of bandwidths of−3dB and −10dB is 1.37nm and 2.31nm respectively, which have excelled the domestic reported level.

In the coming new general optical network, tunable filter is one of important optical devices, and can be used to compose dynamically optical add/drop multiplexer (OADM). Polarization independent integrated acousto-optic tunable filter (IAOTF) is one of devices which have most potential to perform the function[1][2]. Mode splitting and merging are realized by using two symmetrically directional couplers in the IAOTF. Mode polarization is converted by the acousto-optic mode converter when the condition of phase matching is met at the specifically light wavelength. The light wavelength passing the filter can be easily adjusted by changing the frequency of acoustic wave. The Ti diffused technology is adopted to fabricate the device on the X-cut Y propagation LiNbO3 slice. The relation of index difference in the X-cut Y propagation LiNbO3 waveguide with different diffusion conditions is computed in this paper. And the theory of coupling mode is utilized to analyze and design the directional coupler, in which TE/TM mode splitting can be realized. The designed structure is simulated by using BPM software. The extinction ratio of TE/TM mode can be reached 25.1 dB and 24.9 dB respectively.

A novel optical analog-to-digital converter based on optical time division multiplexing (OTDM) is described which uses electrooptic sampling and time-demultiplexing together with multiple electronic analog-to-digital converter(ADC). Compared with the previous scheme, the time-division multiplexer and the time-division demultiplexer are applied in the optical analog-to-digital converter (OADC) at the same time, the design of the OADC is simplified and the performance of the OADC based on time-division demultiplexer is improved. A core optical part of the system is demonstrated with a sample rate of 10 Gs/s. The signals in three channels are demultiplexed from the optical pulses.The result proves our scheme is feasible.

MEMS Fabry-Perot tunable filter is obviously notable because of its mass production and easy integration. Membrane is the key portion of the filter as its structure directly affects the filter's performance and fabricating difficulty. In this paper, some typical membrane structures with different dimensions are simulated. Through making finite element analysis to these simulations and comparing of the results, we find out useful information such that foldaway and spiral cantilevers can achieve longer length in the same membrane area; the longer cantilevers are, the smaller electrostatic force is needed, accordingly the bias voltage is lower and the membrane curvature is smaller, etc. Then we use the information to analyze some important factors affecting membrane's physical and optical performance and make an optimization design.