© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Silicon Photonics: From Fundamental Research to Manufacturing

Novel ultra low power optical memory using liquid crystal

Salah S. A. Obayya, Mahmoud A. Elrabiaey, Hossam M. H. Shalaby, El-Sayed A. Youssef

Published May 21, 2018• 0 citations

Abstract

Nowadays, a huge data traffic requires a high-speed processing, so the use of optical memories is a logical solution for high speed data processing. In this paper, a large-scale parallel integration of wavelength addressable optical bit memories is presented based on three photonic crystal nanocavities (C1, C2, and C3) filled with liquid crystal. Each cavity is storing two different wavelengths, where each wavelength is representing a single bit. We have calculated Q factors in basing and unbiasing states for C1, C2, and C3. Also, the group velocities across the storage cell have been measured in the biased and unbiased cases for all cavities to confirm the storage and confinement. The maximum consumed power for six bits optical memory is only 13 nW.

DOI: 10.1117/12.2306461

Related papers

All-optical on-chip bit memory based on ultra high Q InGaAsP photonic crystal

Akihiko Shinya, Shinji Matsuo, Yosia Yosia +5 more

We demonstrate all-optical bit memory operation with photonic crystal (PhC) nanocavities based on an InGaAsP substrate with a band gap at a wavelength of about 1.3 microm. The optical bistability is based on a refractive index modulation caused by carrier-plasma dispersion. The operating energy required for switching is only 30 fJ, and the minimum optical bias power for bistability is 40 microW, which is about one hundred times less than that required for laser based bistable memories.

Optics Express•Nov 7, 2008•78 citations

Ultralow bias power all-optical photonic crystal memory realized with systematically tuned L3 nanocavity

Eiichi Kuramochi, Kengo Nozaki, Akihiko Shinya +5 more

An InP photonic crystal nanocavity with an embedded InGaAsP active region is a unique technology that has realized an all-optical memory with a sub-micro-watt operating power and limitless storage time. In this study, we employed an L3 design with systematic multi-hole tuning, which realized a higher loaded Q factor (>40 000) and a lower mode volume (0.9 μm3) than a line-defect-based buried-heterostructure nanocavity (16 000 and 2.2 μm3). Excluding the active region realized a record loaded Q factor (210 000) in all for InP-based nanocavities. The minimum bias power for bistable memory operation was reduced to 2.3 ± 0.3 nW, which is about 1/10 of the previous record of 30 nW. This work further established the capability of a bistable nanocavity memory for use in future ultralow-power-consumption on-chip integrated photonics.

Applied Physics Letters•Nov 30, 2015•14 citations

Fast bistable all-optical switch and memory on a silicon photonic crystal on-chip

Takasumi Tanabe, Masaya Notomi, Satoshi Mitsugi +2 more

We demonstrate extremely low-power all-optical bistability by utilizing silicon photonic crystal nanocavities, based on the plasma effect of carriers generated by two-photon absorption. Owing to the high quality factor and the small volume of the nanocavities, the photon density inside the cavity becomes extremely high, which leads to a large reduction in operation power. Optical bistable operation in a single nanocavity permits optical read-write memory operation, which opens the possibility of an integrated optical logic circuit on a single chip, based on photonic crystals. The demonstrated bistable threshold power is 0.4 mW with a set pulse energy of 74 fJ, at a switching speed of <100 ps.

Optics Letters•Oct 1, 2005•325 citations

Nonlinear and adiabatic control of high-Q photonic crystal nanocavities

Masaya Notomi, Takasumi Tanabe, Akihiko Shinya +4 more

This article overviews our recent studies of ultrahigh-Q and ultrasmall photonic-crystal cavities, and their applications to nonlinear optical processing and novel adiabatic control of light. First, we show our latest achievements of ultrahigh-Q photonic-crystal nanocavities, and present extreme slow-light demonstration. Next, we show all-optical bistable switching and memory operations based on enhanced optical nonlinearity in these nanocavities with extremely low power, and discuss their applicability for realizing chip-scale all-optical logic, such as flip-flop. Finally, we introduce adiabatic tuning of high-Q nanocavities, which leads to novel wavelength conversion and another type of optical memories.

Optics Express•Jan 1, 2007•140 citations

All-optical on-chip memory based on ultra high Q InGaAsP photonic crystal nanocavity

Akihiko Shinya, Shinji Matsuo, Yosia Yosia +5 more

We demonstrate all-optical bistable memory operation with 1.3 Q-InGaAsP photonic crystal nanocavities based on refractive index modulation caused by carrier-induced nonlinearity. The minimum bias power for bistability is extremely low at a few tens of muW and the operating energy required for switching is only 30 fJ.

Conference on Lasers and Electro-Optics•May 1, 2008•2 citations

Sub-micron all-optical memory and large scale integration in photonic crystals

Mehmet Fatih Yanik, Hatice Altug, Jelena Vuckovic A +1 more

We demonstrate ultra-high speed, low-power and digital all-optical memory action in photonic nanostructures. We show how large-scale on-chip integration of all-optical devices can be achieved without any optical isolators, even in the presence of reflections

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jan 25, 2006•1 citation

Nowadays, a huge data traffic requires a high-speed processing, so the use of optical memories is a logical solution for high speed data processing. In this paper, a large-scale parallel integration of wavelength addressable optical bit memories is presented based on three photonic crystal nanocavities (C1, C2, and C3) filled with liquid crystal. Each cavity is storing two different wavelengths, where each wavelength is representing a single bit. We have calculated Q factors in basing and unbiasing states for C1, C2, and C3. Also, the group velocities across the storage cell have been measured in the biased and unbiased cases for all cavities to confirm the storage and confinement. The maximum consumed power for six bits optical memory is only 13 nW.

An InP photonic crystal nanocavity with an embedded InGaAsP active region is a unique technology that has realized an all-optical memory with a sub-micro-watt operating power and limitless storage time. In this study, we employed an L3 design with systematic multi-hole tuning, which realized a higher loaded Q factor (>40 000) and a lower mode volume (0.9 μm3) than a line-defect-based buried-heterostructure nanocavity (16 000 and 2.2 μm3). Excluding the active region realized a record loaded Q factor (210 000) in all for InP-based nanocavities. The minimum bias power for bistable memory operation was reduced to 2.3 ± 0.3 nW, which is about 1/10 of the previous record of 30 nW. This work further established the capability of a bistable nanocavity memory for use in future ultralow-power-consumption on-chip integrated photonics.

We demonstrate extremely low-power all-optical bistability by utilizing silicon photonic crystal nanocavities, based on the plasma effect of carriers generated by two-photon absorption. Owing to the high quality factor and the small volume of the nanocavities, the photon density inside the cavity becomes extremely high, which leads to a large reduction in operation power. Optical bistable operation in a single nanocavity permits optical read-write memory operation, which opens the possibility of an integrated optical logic circuit on a single chip, based on photonic crystals. The demonstrated bistable threshold power is 0.4 mW with a set pulse energy of 74 fJ, at a switching speed of <100 ps.

This article overviews our recent studies of ultrahigh-Q and ultrasmall photonic-crystal cavities, and their applications to nonlinear optical processing and novel adiabatic control of light. First, we show our latest achievements of ultrahigh-Q photonic-crystal nanocavities, and present extreme slow-light demonstration. Next, we show all-optical bistable switching and memory operations based on enhanced optical nonlinearity in these nanocavities with extremely low power, and discuss their applicability for realizing chip-scale all-optical logic, such as flip-flop. Finally, we introduce adiabatic tuning of high-Q nanocavities, which leads to novel wavelength conversion and another type of optical memories.