• ETRI Journal
• /
• 제27권5호
• /
• pp.551-556
• /
• 2005

We have demonstrated a high-power widely tunable sampled grating distributed Bragg reflector (SGDBR) laser integrated monolithically with a semiconductor optical amplifier (SOA) having a lateral tapered waveguide, which is the first to emit a fiber-coupled output power of more than 10 dBm using a planar buried heterostructure (PBH). The output facet reflectivity of the integrated SOA using a lateral tapered waveguide and two-layer AR coating of $TiO_2\;and\;SiO_2$ was lower than $3\;{\times}\;10^{-4}\;over$ a wide bandwidth of 85 nm. The spectra of 40 channels spaced by 50 GHz within the tuning range of 33 nm were obtained by a precise control of SG and phase control currents. A side-mode suppression ratio of more than 35 dB was obtained in the whole tuning range. Fiber-coupled output power of more than 11 dBm and an output power variation of less than 1 dB were obtained for the whole tuning range.

• Journal of Mechanical Science and Technology
• /
• 제15권3호
• /
• pp.309-319
• /
• 2001

This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2nm and ∼9%, respectively, at a wavelength of ∼1552nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200$^{\circ}C$ temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132nm/$^{\circ}C$ with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

• 한국광학회지
• /
• 제14권5호
• /
• pp.509-514
• /
• 2003

SOA(Semiconductor Optical Amplifier)를 단일 기판에 집적한 Mach-Zehnder 간섭계 구조의 파장변환기를 제작하여 40 nm 지역폭에 대한 10 Gb/s 파장변환 특성을 조사하였다. 제작된 파장변환기는 BRS(Buried Ridge Structure)형 SOA와 수동 도파로를 butt-joint결합하여 단일 집적한 구조이다. 집적화 과정에서 높은 도파 손실을 발생시키는 p+ InP덮개층을 제거하고 무첨가 InP로 도파로 덮개층 및 전류 차단층을 동시에 형성시키는 새로운 방법을 이용하였고, 모듈 제작에서 경사진 도파로와 광섬유를 효율적으로 광 접속하기 위하여 경사진 광섬유 배열을 제작하여 사용하였다. 이와 같이 제작된 파장변환기 모듈을 이용하여 1535-1575 nm의 40 nm 대역폭에서 1 ㏈ 이하의 power penalty를 갖는 10 Gb/s 파장변환을 구현하였고, 특히 negative penalty를 갖는 파장변환을 성공적으로 구현함으로써 2R(re-amplification, re-shaping) 기능을 제공할 수 있음을 보였다.

• 대한전자공학회논문지SD
• /
• 제37권9호
• /
• pp.1-6
• /
• 2000

InGAAs/InGaAsP 다중양자우물구조에 분순물없는 vacancy 확산으로 지역 선택적인 상호 섞임 현상을 유도하고, 다중 파장 검출이 가능한 집적 광도파로형 photodetector를 제작 및 측정하였다. 다중양자우물구조는 상호섞임에 의해서 밴드갭이 크게 청색편이 하였다. 집적 광수신소자는 p-i-n 구조이며, 밴드갭이 큰 영역과 작은 영역이 광도파로를 따라 일렬이 되도록 항ㅆ다. 광도파로의 폭은 20 ${\mu}m$이며, 각 광수신소자에 길이는 250 ${\mu}m$이다. Tunable 레이저와 편광기를 이용하여, TE/TM 편광된 빛을 광수신소자에 butt-coupling 방법으로 입사하여 소자의 파장 특성을 측정하였다. 제작된 소자는 1480 nm 와 1550 nm 파장 영역을 분리, 수광할 수 있음을 보였다.

• ETRI Journal
• /
• 제45권1호
• /
• pp.163-170
• /
• 2023

We report an electroabsorption modulator (EAM)-integrated distributed Bragg reflector laser diode (DBR-LD) capable of supporting a high data rate and a wide wavelength tuning. The DBR-LD contains two tuning elements, plasma and heater tunings, both of which are implemented in the DBR section, which have blue-shift and red-shift in the Bragg wavelength through a current injection, respectively. The light created from the DBR-LD is intensity-modulated through the EAM voltage, which is integrated monolithically with the DBRLD using a butt-joint coupling method. The fabricated chip shows a threshold current of approximately 8 mA, tuning range of greater than 30 nm, and static extinction ratio of higher than 20 dB while maintaining a side mode suppression ratio of greater than 40 dB under a window of 1550 nm. To evaluate its modulation properties, the chip was bonded onto a mount including a radiofrequency line and a load resistor showing clear eye openings at data rates of 25 Gb/s nonreturn-to-zero and 50 Gb/s pulse amplitude modulation 4-level, respectively.