• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.112-113
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• 2002

Optical bistability can be applied to the optical logic. optical signal processing and optical memory. We have measured the optical bistability of DFB-SOA and demonstrated all-optical OR logic gate using switching characteristics of DFB-SOA.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.280-286
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• 1996

This paper describes operation mechanism of a novel optical waveguide phase modulator with optical bistability characteristics by self electro-optic effect. The fabricated device structure is an optical waveguide modulator, using a refractive index change by an applied electric field, parallel integrated with SEED with an electrical bistability. GaAs/AlGaAs MQW is used as the core layer of the waveguide modulator and the absorption layer of SEED. The absorbed optical power in SEED changes the diode voltage and controls the optical power propagating through the waveguide phase modulator. Optical bistability of waveguide phase modulator is experimentally obtained by using electrical bistability of SEED. Compared to other waveguide modulators, the proposed one has an asset that the lowest optical power is required to generate optical bistability.

• Journal of the Optical Society of Korea
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• v.14 no.2
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• pp.137-141
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• 2010

We report, for the first time to our knowledge, observation of polarization bistability from 1.55-${\mu}m$ wavelength single-mode VCSELs of a conventional cylinder-shape under control of their driving current, and demonstration of all-optical flip-flop (AOFF) operations based on the bistability with optical set and reset pulse injection at a 50 MHz switching frequency. The injection pulse energy was less than 14 fJ. The average on-off contrast ratio of the flip-flopped signals was about 7 dB. These properties of the VCSELs will be potentially useful for future high-speed all-optical signal processing applications.

• Current Optics and Photonics
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• v.6 no.1
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• pp.10-14
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• 2022

Low-threshold optical bistability is essential for practical nonlinear optical applications. Many bistable optical devices based on high-quality-factor resonators have been proposed to reduce the threshold intensity. However, demonstrating high-quality-factor resonance requires complex fabrication techniques. In this work, we numerically demonstrate optical bistability with bound states in the continuum in a simple one-dimensional Si photonic crystal. The designed structure supports bound states in the continuum, producing an ultrahigh quality factor without tough fabrication conditions. The threshold intensity of the designed device is 150 MW/cm² at the optical communication wavelength. This scheme may lead to a new class of nonlinear photonics.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.698-703
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• 2016

We report a new all-optical flip-flop (AOFF) with a quite simple structure, using optical beating in an injection-locked Fabry-Perot laser diode (FP-LD) with optical bistability. While conventional AOFF methods using an injection-locked FP-LD require additional devices such as secondary FP-LDs or polarization controllers for reset operation, the proposed method can be implemented using only a single commercially available FP-LD with set and reset signals. The optical beating induces intensity fluctuations inside the FP-LD, and releases the locking state to the reset state. Even though we demonstrated the AOFF at 100 Mbit/s, we expect that its operation rate could extend to 10 Gbit/s, according to the limit of the FP-LD's frequency response.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.8
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• pp.1-11
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• 2002

A multi-section DFB-LD shows optical bistability subject to externally injected light signal, then it has potential applications such as wavelength conversion and optical logic gates. In this paper, we have studied the optical bistability in multi-section DFB-LD using split-step time-domain model. It is confirmed that the multi-section DFB-LD, which is excited inhomogeneously, shows bistability. The optical bistable characteristics are investigated when input light is injected into a absorptive region. Simulation results show that multi-section DFB-LD works as a flip-flop depending on the set-reset optical pulse which has a few ns in switching time and a few pj in switching energy, so that it can act as a optical logic device. Besides, if we change the carrier lifetime and the differential gain coefficient, it is expected that the response time of optical output signal can be reduced.

• Korean Journal of Optics and Photonics
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• v.9 no.2
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• pp.92-95
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• 1998

In this paper, we have shown theoretically that a nonlinear etalon with nonlinear mirrors exhibits optical bistability. It can be swithed with less power than a nonlinear etalon with linear mirrors.

• Korean Journal of Optics and Photonics
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• v.8 no.6
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• pp.466-470
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• 1997

We fabricated the asymmetric Fabry-Perot etalon which contains amorphous $As_2S_3$ as a spacer layer by using the method of optical multilayer coating and observed the optical bistability with the polarization. Optical thickness of the spacer layer is 2$\lambda$ at $Ar^+$ ($\lambda $=514.5 nm) laser wavelength. Optical bistability was observed at the intensities between 80~100 mW and the experiment shows us that the trends of bistable loop of the reflected and the transmitted lights are quite different depending on the state of polarization. This phenomena can be explained as the phase differences of each polarizations are different in the nonlinear Fabry-Perot etalon.

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.108-109
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 1999.08a
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• pp.158-159
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• 1999