• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.995-997
• /
• 1998

The experimental optical cross-connect based on delivery and coupling switch features all-optical property. It consists of erbium-doped fiber amplifiers, arrayedwaveguide gratings, optical switches and optical combiners. In 4 channel wavelength division multiplexing with 1.6 nm spacing, the difference in power level among channels for output signals from the optical cross-connect was within 2 dB.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2007년도 동계학술발표회 논문집
• /
• pp.187-188
• /
• 2007

• 한국광학회:학술대회논문집
• /
• 한국광학회 2005년도 하계학술발표회
• /
• pp.196-197
• /
• 2005

• ETRI Journal
• /
• 제23권3호
• /
• pp.106-110
• /
• 2001

Subpicosecond all-optical switching method based on the simultaneous two-photon coherence exchange is proposed and numerically demonstrated. The optical switching mechanism is based on the optical field induced dark resonance swapping via nondegenerate four-wave mixing processes. For potential applications of ultrafast all-optical switching in fiber-optic communications, 10-THz channel number independent quantum router is discussed.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 추계학술대회 논문집
• /
• pp.589-590
• /
• 2010

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -1
• /
• pp.1-4
• /
• 2002

The numerical alaysis of optical device, silicabased device, are presented. The purpose of this paper is to simulate and to design a 8-channel optical wavelength division multiplexer(OWDM) based on Mach-Zehnder Interferometer(MZI) with wavelength spacing between channels Δλ=0.8 nm at central wavelength λ=1.55 ${\mu}{\textrm}{m}$. In initial condition fur simulating, we assumed as follows. A channel waveguide is made from silica based P-doped SiO2 core layers in order to coupling with a fiber easily and its core dimension was 6 ${\mu}{\textrm}{m}$$\times$6 ${\mu}{\textrm}{m}$. The core and clad index of channel waveguide were 1.455 and 1.444, separately, at λ=1.55 ${\mu}{\textrm}{m}$. Where, the separation between channel waveguides in coupling region was 3 ${\mu}{\textrm}{m}$. As a result of analysis, a group mode index of channel waveguide was 1.4498370, was gained by Hermite-Gaussian Method(HGM). Also, the channel spacing was determined by the waveguide arm length difference and was Δλ=0.8 nm as like a proposed condition. The central wavelength of a designed-multiplexer was activated about wavelength λ=1.55 ${\mu}{\textrm}{m}$, and we certificated that it can be used to 8-channel optical wavelength division multiplexer/demultiplexer.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.201-204
• /
• 2005

In this paper, based on an extended model containing correlator and soft decision decoding, the capacity is evaluated in the single-user case when the inputs are equiprobable. With this method, we adjusted optical communication over AWGN. It is found that only when bit- signal-to-noise ratio (bit-SNR) is high enough, larger M leads to higher capacity; and for a specific M, the optimal values of PPM time offset parameter Td, which maximize the capacity, are independent of bit-SNR. In this paper, the capacity of UWB system in optical fiber over AWGN is proven to improve 1.73 times larger than AWGN channel Capacity.

• Journal of the Optical Society of Korea
• /
• 제2권1호
• /
• pp.22-25
• /
• 1998

We present a spectrum broadening technique to improve the signal-to-noise ratio of spectrum sliced incoherent light sources using the fiber four-wave mixing effect which occurs in a nonlinear loop mirror located at the receiver. The initial transmission channel bandwidth of 0.92 nm was increased to 1.62 nm in the nonlinear loop mirror at the optical receiver, which enhances the signal-to-noise ratio to a desired value. Using this technique, we have demonstrated the transmission of a 2.5 Gb/s NRZ signal with the 0.92 nm bandwidth through a 80 km dispersion-shifted fiber. The measured transmission penalty was less than 0.2 dB at $1{\imes}10^{-10}$ BER.

• Journal of the Optical Society of Korea
• /
• 제9권1호
• /
• pp.1-5
• /
• 2005

Using tightly focused femtosecond laser pulses, we produce an optical waveguide and optical devices in transparent materials. This technique has the potential to generate not only channel waveguides, but also three-dimensional optical devices. In this paper, an optical splitter and U-grooves, which are used for fiber alignment, are simultaneously fabricated in a fused silica glass using near-IR femtosecond laser pulses. The fiber aligned optical splitter has a low insertion loss, less than 4㏈, including an intrinsic splitting loss of 3㏈ and excess loss due to the passive alignment of a single-mode fiber. Finally, we demonstrate the utility of the femtosecond laser writing technique by fabricating gratings at the surface and inside the silica glass.

• ETRI Journal
• /
• 제27권4호
• /
• pp.446-448
• /
• 2005

Using tightly focused femtosecond laser pulses, we produce an optical waveguide and devices in transparent materials. This technique has the potential to generate not only channel waveguides, but also three-dimensional optical devices. In this paper, an optical splitter and U-grooves, which are used for fiber alignment, are simultaneously fabricated in a fused silica glass using near-IR femtosecond laser pulses. The fiber- aligned optical splitter has a low insertion loss, less than 4 dB, including an intrinsic splitting loss of 3 dB and excess loss due to the passive alignment of a single-mode fiber. Finally, we present an output field pattern, demonstrating that the splitting ratio of the optical splitter becomes approximately 1:1.