Integrated magnetooptic Bragg cell modules and applications.

摘要

The technical maturity for the excitations of magnetostatic waves (MSW's) and guided optical waves (GOW's) in a common ferromagnetic substrate, yttrium ion garnet-gadolinium gallium garnet (YIG-GGG) waveguide structure, has facilitated various studies on the interactions between the GOW's and the MSW's and the resulting guided-wave magnetooptic (MO) devices. The unique features inherent with this new class of devices, such as the capability of direct operation at the carrier frequency of 2 to 20 GHz and beyond, very high speed (up to nano second range), very large bandwidth realized by dual-tuning mechanism, and simple fabrication techniques for the MSW transducer, have suggested a variety of applications in areas such as RF signal processing and fiber optic communication.; In the dissertation research, explicit expressions for the RF magnetization of magnetostatic forward volume waves (MSFVW) and magnetostatic backward volume wave (MSBVW) generated by a microstripline transducer in a YIG-GGG layered structure have been derived for the first time. The behavior of the RF magnetization as a function of various physical and geometrical parameters and its influence on the design of high-performance guided-wave MO Bragg cells are studied in detail. A good agreement between computed and experimental results has been obtained. As an application of the analysis, a MSBVW-based MO Bragg cell was designed and constructed for the first time, and it was used successfully to demonstrate light beam scanning.; A new and novel wideband integrated optical frequency shifter module that utilizes noncollinear guided-wave MO Bragg diffraction from the MSFVW in a bismuth-doped YIG-GGG waveguide has also been devised and realized. Constancy in the output angle of the frequency-shifted light beam is facilitated by simultaneous tuning of the carrier frequency of the RF drive signal and the bias magnetic field using an electronic synchronizer. The device operating at the optical wavelength of 1.302 {dollar}mu{dollar}m and the carrier frequency at X-band has demonstrated desirable characteristics including large frequency shift (11.025 GHz), very large tunable bandwidth (3.56 GHz), and high tuning speed (10 {dollar}mu{dollar}s).