Design and characterization of a mode-splitting Ψ-junction

Abstract

It will be shown in this paper, that the mode conversion factor (MCF) as defined for Y-junctions, can be profitably the three lowest-order modes of a channel waveguide. Accordingly, these so-called mode-splitting Q-junctions were designed for implementation in PECVD SiON-technology. Propagation calculations point to crosstalk levels well below-20 dB at 10-20 mm junction length. The produced q-junctions show crosstalk Of at a desired crosstalk level. We have realized several modesplitting junctions in SiON-technology using this strategy. butions over the branches, intensity profiles in the multimodal branch and the beat-pattern of light scattered out of that branch. The characterizations show that a @-junction with a intermodal crosstalk of less than-17 dB has been realized. TO the best applied for the design of three branch junctions for These junctions were characterized by analyzing power distri-I. INTRODUCTION 11. DEVICE PRINCIPLES ULTIBRANCH junctions like the well-known Yjunction (1 + 2) or the less-known Q-junction (1 The mode-splitting behavior of multibranch junctions [2]

Laguerre-Gaussian mode division multiplexing in multimode fiber using SLMs in VCSEL arrays

“…In addition, q-plates have been fabricated from liquid-crystal slabs to convert a left circularly polarized beam into a helically phased beam with right circular polarization, or vice versa [27]. Furthermore, on-plane mode couplers for combining and separating different spatial channels [28][29][30][31], switches for routing different channels [32] have also been developed.…”

On-chip two-mode division multiplexing using tapered directional coupler-based mode multiplexer and demultiplexer

“…The key to realize on-chip MDM is an efficient mode (de)multiplexer. On-chip mode multiplexers based on weakly guiding asymmetrical Ψ-and Y-junctions have been suggested [4][5][6][7]. Multimode interferometers have also been proposed as mode multiplexers [8,9].…”

Experimental analysis of the whispering-gallery modes in a cylindrical optical microcavity

“…Second, the resolution is diffraction limited to, at best, half of the wavelength of the detected light. [7][8][9] Finally, it is not possible to observe locally some crucial phenomena, such as mode conversion, polarization conversion, and the reversal of propagation direction, inside the devices. For example, to understand the crossover between emission from whispering-gallery modes (WGM's) to bow-tie modes 1 inside low-threshold microlasers it is important to measure locally inside the microlaser.…”

“…One can confirm the outcome of the simulations by comparing the results obtained with other analytical approaches but more importantly by experimental verification. Most current experimental methods are restricted to characterization with respect to the functional behavior by measuring the input-output response [5][6][7] or to conventional optical imaging techniques [7][8][9] of the device. With the socalled black-box response method [5][6][7] the throughput of the device is measured and compared with the theoretical predictions.…”

“…However, what occurs inside the device remains hidden. With a conventional optical microscope, [7][8][9] the intensity profiles inside the cavity are made visible. However, such direct imaging of integrated optical devices has some drawbacks.…”