• ETRI Journal
• /
• 제28권5호
• /
• pp.615-620
• /
• 2006

In this paper, we discuss the quantification of Mach-Zehnder interferometer (MZI) thermal stabilization which is needed in optical phase shaped binary transmission (PSBT) links. Considering the thermo-optic and thermal expansion effects, we revisit the analytical expression for the thermal drift (GHz/$^{\circ}C$) of the MZI center frequency (denoted here by the 'MZI spectral drift'). An MZI is then used in an experimental transmission system using the optical PSBT format. We study the effect of spectral MZI drift by using a thermally stabilized interferometer and applying a frequency shift to the optical carrier. By using the thermal drift coefficient of the MZI, we find that to ensure low bit error rate fluctuations due to the MZI drift, the thermal stabilization of the device must have an accuracy of $0.5^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.223-223
• /
• 2009

In this paper, designed and simulated Power Splitter (PS) integrated Mach-Zehnder interferometer (MZI) based planar type optical waveguide devices (which is called here a PS-MZI). The PS-MZI optical waveguide sensor was preceded by a Y-junction, which splits the input power between the sensor, and a reference branch, to minimize the effect of optical power variations. The PS-MZI optical waveguide sensor induced changing phases of the incident beam, which had fallen upon the waveguide through computer simulation, according to the small changes in the index of refraction, thus beam intensity was changed. The waveguide were optimized at a wavelength of 1550 nm and fabricated according to the design rule of 0.45 delta%, which is the difference of refractive index between the core and clad. The fabrication of PS-MZI optical waveguide sensor was performed by a conventional planar lightwave circuit (PLC) fabrication process. The PS-MZI optical waveguide that was fabricated to be applied as a biosensor revealed a low insertion loss and a low polarization-dependent loss. After having etched the over-clad at the sensor part in the MZI optical waveguide that was fabricated, Ti deposition was made on the adhesion layer, and then Au thin-film deposition was carried out thereon. In addition, its optical properties were measured by having changed the index of refraction oil at the sensing part of the MZI. To apply the planar type PS-MZI optical waveguide as a biosensor, a detection test for Staphylococcus aureus was conducted according to changes in concentration, having adopted Ti-alkoxide as ligand. The detection result of the S. aureus by the PS-MZI optical waveguide sensor was possible to the level of $10^1$ CFU/ml.

• ETRI Journal
• /
• 제34권6호
• /
• pp.946-949
• /
• 2012

We present the optimization of a birefringence-enhanced-waveguide (BWG)-based polarization beam splitter (PBS) in a Mach-Zehnder interferometer (MZI) configuration and analyze the structure-dependent or polarization-dependent phase difference, using a delay-line MZI (DL-MZI). We fabricate the DL-MZI using silica-based planar lightwave circuit technology and, using the DL-MZI, demonstrate the ability to optimize a PBS by measuring the birefringence of the BWG and structure-dependent phase offset.

• 대한전자공학회논문지SD
• /
• 제43권1호
• /
• pp.13-16
• /
• 2006

병렬 SOA-MZI 구조들을 이용하여 XOR NOR, OR, 그리고 NAND 기능들을 가진 전광 복합 논리 게이트들을 제안하고 100Gbps에서 실험적으로 구현했다. 제안된 구조는 높은 소광 비를 가지며 복합적인 논리 기능들을 동시에 수행할 수 있다.

• 대한전자공학회논문지SD
• /
• 제41권5호
• /
• pp.9-14
• /
• 2004

WDM 광통신 시스템에서 중요한 소자는 여러 개의 광신호를 결합, 분리시켜주는 멀티플렉서, 디멀티플렉서 그리고 특정파장을 선택할 수 있는 필터이다. 그러나, 이러한 시스템의 형태는 집적소자의 형태가 아니기 때문에 손실이 비교적 크고 시스템을 소형화, 경량화 하는데 어려움이 있어 이를 보완하기 위한 집적형태의 소자가 필요하다. 본 논문에서는 WDM 광통신 시스템에서 사용할 수 있는 집적 소자 형태의 OADM의 설계를 위해 FBG와 MZI를 이용하여 구성하고, 이를 컴퓨터 시뮬레이션을 통해 최적의 설계값을 제시하였으며, 실험을 통하여, 제작된 OADM의 특성을 측정함으로써 시뮬레이션을 통해 얻어진 설계값과 비교, 분석하였다. 제안한 OADM은 선폭을 조절함으로써 선택할 수 있는 파장의 범위가 넓어져 DWDM 시스템에서도 적합함을 검증할 수 있었다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.390-390
• /
• 2008

In this paper, we have designed and fabricated optical waveguides based on the Mach-Zehnder Interferometer (MZI) for application to sensor. The evanecent-wave sensor based on the MZI principle has sufficiently high sensitivity to measure the change of the refractive index on surface of a waveguide. The waveguides were optimized at a wavelength of 1550 nm and fabricated according to the design rule of 0.45 delta%, which is the difference of refractive index between the core and clad. The fabrication of MZI optical waveguides was performed by a conventional Planar Lightwave Circuit (PLC) fabrication process. The fabricated MZI optical waveguide device was measured. According to the measurement result, the insertion loss of MZI optical waveguide device was below 3.5 dB and the polarization dependent loss (PDL) was within 0.1dB. In addition, we analyzed optical properties of MZI sensor according to the refractive index change of the sensor arm.

• 한국통신학회논문지
• /
• 제31권1A호
• /
• pp.11-15
• /
• 2006

CW-HB(continuous wave-holding beam)를 이용하여 전치 증폭되는 SOA-MZI(semiconductor optical amplifier-Mach-Zehnder interferometer) 파장변환기가 제안되고 10Gb/s에서 실험적으로 검증되었다. 바이어스 전류만으로 전치증폭기를 제어하던 기존의 방법과 비교할 때, 제안된 CW-HB 제어 방법은 IPDR(input power dynamic range)의 개선 측면에서는 20dB 정도로 유사하나 출력신호의 왜곡을 제거하여 Q 파라미터를 $2{\sim}3$ 정도 향상시키고 낮은 NF(noise figure)를 달성하여 $2{\sim}5dB$ 정도 더 높은 소광 비를 얻을 수 있어서 매우 우수하다.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제5C권6호
• /
• pp.257-263
• /
• 2005

WDM optical communication system requires wavelength division multiplexing, reverse multiplexing and optical filter. OADM is a device that can separate or combine specific wavelength of channel from the transmission line. This paper suggests OADM that uses 2 steps FBG based on MZI structure. The OADM that uses 2 steps FBG can minimize the system size and reduce the value of side lobe remarkably. The results obtained in this paper can be used for design and application of OADM that uses 2 steps FBG.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
• /
• pp.131-135
• /
• 2003

WDM(Wavelength division multiplexing) light wave communication system requires MUX/DeMUX and optical filter OADM can be used to extract and add the specific wavelength channel from the transmission line. In this paper, we propose the OADM based on MZI and cascade FBG. It is able to minimize system and reduce sidelobe. So, we have considered MZI structure and 3dB coupler. Using the coupled mode theory. We also analyze out characteristics of OADM and experiment. From results obtained by experiment and computer. Simulation, the proposed OADM with cascade FBG works well. we hope that the obtained result in this paper con be used as the data to design the OADM with cascade FBG.

• 정보통신설비학회논문지
• /
• 제3권2호
• /
• pp.51-60
• /
• 2004

A광섬유 용융인장방법에 의해서 100GHz 채널간격을 갖는 DWDM용 8채널 광다중화기를 제작하였다. 8채널 광다중화기는 전광섬유형 Mach Zehnder 간섭계(MZI)를 3단으로 다단 연결하여 제작되었으며, 광다중화기 채널별 출력파장의 삽입손실을 균일하게 하기 위하여 파장에 대한 삽입손실변화가 적은 파장무의존형 커플러(WFC)를 이용하여 전광섬유형 MZI를 제작하였다. 광다중화기를 구성하는 광섬유형 MZI를 제작함에 있어서 경로차에 따른 출력 파장간격의 변화를 시뮬레이션을 통하여 알아보았고 다단연결에 의한 광다중화기 구현방법을 논의하였다. 전용 제작 장치를 이용하여, 전광섬유형 MZI를 제작하였으며, 미세한 파장을 저절하기 위해서, $CO_2$ 레이저를 이용하였다. 제작된 8채널 광다중화기는 평균 삽입 손실 2.1dB, 5.5dB에서의 통과대역폭이 0.8nm 이며, 25dB의 채널 Crosstalk를 갖는 특성을 얻을 수 있었고, 편광의존손실은 0.06dB 였다.