Multimode interference photonic switches

Abstract

Abstract. Photonic switches are becoming key components in advanced optical networks due to their various applications in optical communication. One of the key advantages of photonic switches is the fact that they redirect or convert light without any optical to electronic conversions and vice versa. As one type of optical switch, multimode interference ͑MMI͒ switches have received more attention in recent years due to their significant role. The structure and operation principle of various types of MMI switches are introduced, and the recent progresses of MMI switches are also discussed.

Use of Reconfigurable IM Regions to Suppress Propagation and Polarization Dependent Losses in a MMI Switch

“…Various materials such as polymers, SiO 2 -SiON, SOI, LiNbO 3 , III-V group semiconductors and their composites have been used as a backplane to develop multimode waveguides to implement optical couplers and switches. [1][2][3][4][5][6][7][8][9] Such waveguides are suitable to realize many optical devices utilizing their self-imaging principle and possess various characteristics such as compactness, relaxed fabrication tolerance, large optical bandwidth, and polarization insensitivity. [8][9][10] Design of ultra-short couplers and switches based on MMI waveguides have been achieved by eliminating photonic confinement to change their behaviors or by alteration in the imaging length with suitable index variance.…”

“…[1][2][3][4][5][6][7][8][9] Such waveguides are suitable to realize many optical devices utilizing their self-imaging principle and possess various characteristics such as compactness, relaxed fabrication tolerance, large optical bandwidth, and polarization insensitivity. [8][9][10] Design of ultra-short couplers and switches based on MMI waveguides have been achieved by eliminating photonic confinement to change their behaviors or by alteration in the imaging length with suitable index variance. [5,6] In recent, researchers has shown a great interest for modeling of polarization independent photonic switches for wide wavelength spectrum, low losses and CT levels using MMI waveguiding structures.…”

“…Singh, V. Janyani, P. Yadav with the occurrence of multiple self-images. [8] This change in the refractive index is the prime factor behind altering the phase relation between the self-images, which ultimately modifies the output image and switches the light between the output waveguides. MMI structures usually realize optical functions by tuning the refractive index of the image modulation region, located within the MMI section.…”

“…1, the confinement guide regions are shown, which allows the Figure 1: Layout of 2×2 MMI-switch with IM region, ref. [8] light to pass through the region. Distribution of the optical intensities in the MMI waveguides occurs in accordance to the beat length, defined as follows.…”

Optimization of a thermally tuned silicon-based reconfigurable optical power splitter with thermal isolations

“…The MMI-based optical power splitter is very suitable for achieving the reconfigurable function, 14,15 which may derivate novel integrated and compact photonics. 16 By designing the MMI structure and modulating the refractive index of specific multimode (self-images) areas, the phase shifts in the MMI coupler can be accurately controlled, [17][18][19] and different splitting ratios at the output ports can then be realized.…”