Integrated acoustooptic circuits and applications

Abstract

The recent development of titanium-indiffusion proton-exchange (TIPE) microlenses and lens arrays has made possible the construction of a variety of single- and multichannel integrated acoustooptic (AO) and acoustooptic-electrooptic (EO) circuits in LiNbO(3) channel-planar waveguides 0.1x1.0x2.0 cm(3) in size. These hybrid AO and AO-EO circuits can be fabricated through compatible and well-established technologies. The most recent realization of ion-milled microlenses and lens arrays together with the recent development of gigahertz AO Bragg modulators and EO Bragg modulator arrays have also paved the way for construction of similar but monolithic AO and AO-EO GaAs/GaAlAs waveguides of comparable size. Both types of integrated AO and AO-EO circuits suggest versatile applications in communications signal processing, and computing. Efficient and simultaneous excitation of the channel waveguide array using an ion-milled planar microlens array has facilitated the demonstration of some of these applications.

<title>Novel integrated optical beam former for phased-array antennas</title>

“…A laser source is butt-coupled to a Z-cut LiNbO3 single crystal; the laser beam is first expanded and, then, collimated by a double non linear grating system. The possibility ofrealizing microlenses by using the titanium indiffusion proton exchange (TIPE) fabrication technique [8] suggests the excitation of the guided wave into the channel waveguides as shown in Fig. I , for a wide variety of both single and multi-channel acoustooptic and electrooptic integrated circuits.…”

<title>Design and performance of GaAs-based guided-wave heterodyne circuits for signal processing</title>

“…In the last few years, the optoelectronic technologies are becoming more and more mature for fabricating a number of active and passive guided-wave devices to be used in complex circuits for signal processing, optical computing, optical communications and sensing applications [1][2]. The interest devoted to the optical architectures is mainly due to the advantages allowed with respect to analogous electronic devices and circuits, in terms of lower power consumption, higher data throughput, smaller size and weight, larger bandwidth, and lower sensitivity to environmental parameters.…”

“…Many guided-wave circuits based on SAW propagation have been already proposed and demonstrated for performing spectral analysis, convolution, correlation, and multichannel radar applications [1,2,4,5], particularly using ferroelectric materials such as LiNbO and semiconductors, such as GaAs and related compounds and Si. Among them, some configurations of integrated optical spectrum analyzers have been proposed with good optical performances, but with inirinsic low dynamic range (< 25 dB) due to the squared response of output photodiode array.…”

Diffraction of Guided Optical Waves by Surface Acoustic Waves in Proton-Exchanged 128� Rotated Y-Cut LiNbO3

“…Various acousto-optic devices including light modulators, beam deflectors, filters etc. have been developed on that basis [2]. The choice of material for such devices is determined by requirements of the efficient generation of SAWs over a large bandwith, the ability to produce good-quality optical guiding layers, and the efficient acousto-optic interaction.…”