Ultrasmall in-plane photonic crystal demultiplexers fabricated with photolithography

Abstract

We demonstrate ultrasmall demultiplexers based on photolithographic photonic crystals. The footprint of the demultiplexers is 110 μm² per channel. Our in-plane demultiplexers are clad with silica, which makes them stable and easy to integrate with other silicon photonic devices. We describe two types of demultiplexers with spacings of 136 and 267 GHz between channels for application to dense wavelength division multiplexing. Integrated titanium nitride heaters allow us to precisely control the channel wavelength. We report a 2.5 Gbps transmittance experiment with sufficiently small crosstalk and discuss ways of achieving even lower crosstalk between channels.

Ultrahigh‐Q Photonic Nanocavity Devices on a Dual Thickness SOI Substrate Operating at Both 1.31‐ and 1.55‐µm Telecommunication Wavelength Bands

“…Regarding the PC pattern on the dual thickness substrate, it can be also written using photolithography. Therefore, we consider that the use of a dual thickness substrate will be applicable to mass production using CMOS fabrication machinery with large wafers . This technical approach can realize the integrated Si photonic chip for O/C bands.…”

“…Therefore, we consider that the use of a dual thickness substrate will be applicable to mass production using CMOS fabrication machinery with large wafers. [5,27,28,51,52] This technical approach can realize the integrated Si photonic chip for O/C bands. The balanced plasma-etching time in both structures would be obtained by the optimizations of the etching condition and the devece geometry.…”

Ultrasmall in-plane demultiplexer enabled by an arrayed one-dimensional photonic crystal nanobeam cavity

“…To realize smaller WDM demultiplexers, those based on Si PC are being developed. [17][18][19][20][21][22][23][24] For example, Song et al 18 demonstrated two-dimensional (2-D) PC cavities-based 16-channel WDM demultiplexer with 628-GHz channel spacing, and the footprint of per channel is 12 μm 2 . Takahashi et al 21 demonstrated 2-D PC cavities-based 32-channel out-of-plane WDM demultiplexer with 100-GHz channel spacing, and the footprint of per channel is ∼130 μm 2 .…”

“…Takahashi et al 21 demonstrated 2-D PC cavities-based 32-channel out-of-plane WDM demultiplexer with 100-GHz channel spacing, and the footprint of per channel is ∼130 μm 2 . Ooka et al 24 demonstrated 2-D PC cavities-based eight-channel in-plane WDM demultiplexer with 267-GHz channel spacing, and the footprint of per channel is 110 μm 2 . Among these Si PC-based WDM demultiplexers mentioned above, all of them are based on 2-D PC cavity platforms.…”

“…Moreover, the footprints per channel are 22.5 μm 2 , which is decreased by more than five times compared to the per channel in the recent 2-D PC-based WDM demultiplexers. 21,24 In addition, it is worth mentioning that, by changing the cavity length on the subnanometer scale, the peak wavelengths at 100-GHz spacing in the wavelength range between 1330 and 1420 nm can be successfully designed, which is potentially a promising platform for developing ultracompact 100-GHz spaced dense WDM system with more than 100 channels.…”