Waveguide optical isolator based on Mach–Zehnder interferometer

Abstract

A waveguide optical isolator based on nonreciprocal interference is demonstrated. Ridge waveguides are fabricated in a Mach–Zehnder configuration on a single film of bismuth-, lutetium-, neodymium-iron garnet. With this design, no polarizers are required to achieve extinction in the backward propagation direction. This isolator exhibits a 19 dB extinction ratio at λ=1.54 μm. A flat wavelength dependence, to within 2 dB, has been observed in the range between 1.49 and 1.57 μm.

Silicon ring isolators with bonded nonreciprocal magneto-optic garnets

“…The optical isolation can be achieved by nonreciprocal mode conversion [1], nonreciprocal waveguide loss [2,3], and nonreciprocal phase shift [4,5]. The isolator utilizing nonreciprocal mode conversion can convert backward light to a radiation mode and result in higher optical loss, but phase matching between the modes is always an issue.…”

Influence of the Laser Repetition Rate on Crystalline Structure, Composition and Magnetic Properties of Laser Deposited Y3Fe5O12/Gd3Ga5O12(111) Films

“…With sometimes sophisticated substitutions, garnet films have been proposed for two important applications in the past, as bubble memory films and for magnetostatic wave devices [1,2]. In the past two decades, interest in their magnetooptical prpoperties has grown [3][4][5][6].…”

Enhancing optical isolator performance in nonreciprocal waveguide arrays

“…Driven by industrial demands, much effort has been dedicated to the miniaturization and integration of these optical components in photonic circuits [1][2][3][4][5][6][7][8][9][10]. Along these lines, various prototypes with varying degrees of isolation efficiency (the ratio of backreflected light reaching the source to forward transmitted light) and forward transmission efficiency have been proposed and implemented.…”

“…We focus on silicon-on-insulator platforms where nonreciprocity is introduced into the arrays via iron garnet cover layers magnetized transversely to the propagation direction. Transversely magnetized waveguides are known to experience a nonreciprocal phase shift in opposite propagation directions [3][4][5]. It is assumed that a magneto-optic gyrotropy gradient has been established across the array via composition gradients, either as a result of the selective deposition of different garnet compounds on each of the waveguide elements, or via a lateral combinatorial-materials-synthesis, represented schematically in Fig.…”