• 천문학논총
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• 제32권1호
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• pp.41-43
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• 2017

AKARI performed about 10,000 spectroscopic observations with the Infrared Camera (IRC) during its mission phase. These IRC observations provide unique spectroscopic data at near- and mid-infrared wavelengths for studies of the next few decades because of its high sensitivity and unique wavelength coverage. In this paper, we present the current status of the activity for improving the IRC spectroscopic data reduction process, including the toolkit and related data packages, and also discuss the goal of this project.

• Current Optics and Photonics
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• 제5권2호
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• pp.186-190
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• 2021

In this study, a compact, picosecond, mid-infrared 3.8 ㎛ MgO:PPLN optical parametric oscillator (OPO) laser output with high peak power is realized using a master oscillator power amplifier (MOPA) 1 ㎛ solid-state laser seeded by a picosecond fiber laser as the pump source. The pump source was a 50 MHz and 10 ps fiber seed source. After AOM pulse selection and two-stage solid-state amplification, a 1,064 nm laser output with a repetition frequency of 1-2 MHz, pulse width of 9.5 ps, and a maximum average power of 20 W was achieved. Furthermore, a compact short cavity with a unsynchronized pump is adopted through the design of an OPO cavity structure. When the injection pump power was 15 W and the repetition frequency was 1 MHz, the average output power of idler light was 1.19 W, and the corresponding peak power was 119 kW. The optical conversion efficiency was 7.93%. When the repetition frequency was increased to 2 MHz, the average output power of idler light was 1.63 W, the corresponding peak power was 81.5 kW, and the optical conversion efficiency was 10.87%. At the same time, the output wavelength was measured at 3,806 nm, and the beam quality was MX2 = 3.21 and MY2 = 3.34.

• ETRI Journal
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• 제32권2호
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• pp.319-326
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• 2010

Photonics offers a solution to data communication between logic devices in computing systems; however, the integration of photonic components into electronic chips is rather limited due to their size incompatibility. Dimensions of photonic components are therefore being forced to be scaled down dramatically to achieve a much higher system performance. To integrate these nano-photonic components, surface plasmon-polaritons and/or energy transfer mechanisms are used to form plasmonic chips. In this paper, the operating principle of plasmonic waveguide devices is reviewed within the mid-infrared spectral region at the 2 ${\mu}m$ to 5 ${\mu}m$ range, including lossless signal propagation by introducing gain. Experimental results demonstrate that these plasmonic devices, of sizes approximately half of the operating free-space wavelengths, require less gain to achieve lossless propagation. Through optimization of device performance by means of methods such as the use of new plasmonic waveguide materials that exhibit a much lower minimal loss value, these plasmonic devices can significantly impact electronic systems used in data communications, signal processing, and sensors industries.

• 진공이야기
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• 제2권1호
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• pp.17-20
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• 2015

In this article, a historical and scientific review on the development of an ultrafast electron microscope is supplied, and the challenges in further improvement of time resolution under sub-picosecond or even sub-femtosecond scale is reviewed. By combining conventional scanning electron microscope and femtosecond laser technique, an ultrafast electron microscope was invented. To overcome its temporal resolution limit which originates from chromatic aberration and Coulomb repulsion between individual electrons, a generation of electron pulse via strong-field photoemission has been investigated thoroughly. Recent studies reveal that the field enhancement and field accumulation associated with the near-field formation at sharply etched metal nanoprobe enabled such field emission by ordinary femtosecond laser irradiation. Moreover, a considerable acceleration reaching 20 eV with near-infrared laser and up to 300 eV acceleration with mid-infrared laser was observed, and the possibility to control the amount of acceleration by varying the incident laser pulse intensity and wavelength. Such findings are noteworthy because of the possibility of realizing a sub-femtosecond, few nanometer imaging of nanostructured sample.in silicon as thermoelectric materials.

• 한국결정성장학회지
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• 제33권6호
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• pp.250-254
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• 2023

본 연구에서는 중적외선 영역에서 투과 성능이 우수하며, 높은 굴절률을 갖는 Li₂O-BaO-Ga₂O₃-TeO₂-TiO₂-GeO₂계 유리를 합성하였으며, 각 성분의 함량 변화에 따른 열적, 광학적 특성을 분석하였다. Li₂O-BaO-Ga₂O₃-TeO₂-TiO₂-GeO₂ 계 유리에서, TeO₂의 함량이 증가함에 따라 굴절률이 증가하며 동시에 유리 전이 온도가 낮아짐을 확인하였다. 또한 BaO의 함량이 증가함에 따라 아베수의 감소 없이 굴절률이 증가하였다. IR cut-off 파장은 TeO₂ 및 BaO의 함량이 증가함에 따라 장파장으로 이동하는 것을 확인하였으며 이는 TeO₂ 및 BaO의 큰 몰질량 때문인 것으로 예상된다. Li₂O의 경우, BaO와 치환 형태로 첨가되었으며, 그 함량이 늘어날수록 굴절률의 큰 감소 없이, 유리 전이온도를 감소시킬 수 있는 것으로 확인되었다.

• 한국광학회지
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• 제30권4호
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• pp.154-158
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• 2019

기존에 개발되었던 광 파라메트릭 발진기를 이용해 중적외선 분광기의 성능 평가 장치를 구축하였다. 사용된 중적외선 광 파라메트릭 발진기는 파장 1064 nm의 연속파 레이저로 펌핑되는 fan-out형 MgO-doped periodically poled lithium niobate (MgO:PPLN) 비선형 결정을 사용하여 파장가변 영역이$ 2.5{\sim}3.6{\mu}m$인 공중심 공진기 구조를 가지고 있다. 이 광 파라메트릭 발진기에 중적외선용 적분구 및 푸리에 변환 적외선 광 스펙트럼 분석기를 결합하여 중적외선 분광기 성능평가 장치를 구축하였다. 구축된 평가장치를 국내에서 개발한 중적외선용 분광기에 적용, 성능 평가를 진행함으로써 본 평가 장치를 분광기의 파장 분해능, 신호대잡음비, 분광 떠돌이광 등의 성능을 평가하는데 활용할 수 있음을 보였다.

• 천문학논총
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• 제32권1호
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• pp.213-217
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• 2017

The recent updates of the North Ecliptic Pole deep ($0.5deg^2$, NEP-Deep) multi-wavelength survey covering from X-ray to radio-wave is presented. The NEP-Deep provides us with several thousands of $15{\mu}m$ or $18{\mu}m$ selected galaxies, which is the largest sample ever made at these wavelengths. A continuous filter coverage in the mid-infrared wavelength (7, 9, 11, 15, 18, and 24 µm) is unique and vital to diagnose the contributions from starbursts and AGNs in the galaxies out to z=2. The new goal of the project is to resolve the nature of the cosmic star formation history at the violent epoch (e.g. z=1-2), and to find a clue to understand its decline from z=1 to present universe by utilizing the unique power of the multiwavelength survey. The progress in this context is briefly mentioned.

• 한국광학회지
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• 제26권1호
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• pp.30-37
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• 2015

섬광의 복사온도를 측정 할 수 있는 장치를 설계하고 제작하였다. 본 논문에서는 중 원적외선 영역에서 광원의 스펙트럼 복사휘도(spectral radiance)를 측정하여 두 영역의 복사휘도 비로부터 섬광의 복사온도를 구할 수 있는 장치를 설계 및 제작하였다. 중 원적외선 영역에서 파장에 따른 복사휘도를 측정하기 위하여 광학적 대역 투과필터로 입사광을 파장에 따라 분할하고 각각의 파장으로 분할된 광을 동시에 적외선 검출기로 검출하여 입력광의 파장에 따른 복사휘도를 측정하였다. 제작된 장비로 섬광의 온도를 측정한 결과 1393K와 1455K의 온도를 얻었다. 제작된 복사온도 측정 장치는 섬광의 광원 정보를 파악하는데 중요하게 활용될 수 있으며, 섬광의 효과를 위한 M&S에 활용될 수 있다.

• 천문학회보
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• 제39권2호
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• pp.70.2-70.2
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• 2014

Galaxy clusters, the largest gravitationally bound systems, are an important means to place constraints on cosmological models. Moreover, they are excellent places to test galaxy evolution models in connection to the environments. To this day, massive clusters have been found unexpectedly(Kang & Im 2009, Durret et al. 2011, Tashikawa et al. 2012) and evolution of galaxies in cluster have been still controversial (Elbaz et al. 2007, Cooper et al. 2008, Tran et al. 2009). Finding galaxy cluster candidates in a wide, deep imaging survey data will enable us to solve the such issues of modern extragalactic astronomy. We have used multi-wavelength data from the UKIRT Infrared Deep Sky Survey Deep Extragalactic Survey (UKIDSS DXS/J and K bands), Spitzer Wise-area InfraRed Extragalactic survey (SWIRE/two mid-infrared bands), the Panoramic Survey Telescope and Rapid Response System (PAN-STARRS/ g, r, i, z, y bands) and Infrared Medium-deep Survey(IMS/J band). We report new candidates of galaxy clusters and properties of their member galaxies in one of the wide and deep survey fields ELAIS-N1, European Large Area ISO Survey North1, covering sky area of $8.75deg^2$.

• 천문학회보
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• 제39권1호
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• pp.48.1-48.1
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• 2014

Galaxy clusters, the largest gravitationally bound systems, are an important means to place constraints on cosmological models. Moreover, they are excellent places to test galaxy evolution models in connection to the environments. To this day, massive clusters have been found unexpectedly(Kang & Im 2009, Durret et al. 2011, Tashikawa et al. 2012) and evolution of galaxies in cluster have been still controversial (Elbaz et al. 2007, Cooper et al. 2008, Tran et al. 2009). Finding galaxy cluster candidates at z>1 in a wide, deep imaging survey data will enable us to solve the such issues of modern extragalactic astronomy. We report new candidates of galaxy clusters and their physical properties in one of the wide and deep survey fields, European Large Area ISO Survey North1(ELAIS-N1) and North2(ELAIS-N2) fields, covering sky area of and each. We also suggest a new useful color selection technique to separate 1 < z < 2 galaxies from low-z galaxies by combining multi-wavelength data from the UKIRT Infrared Deep Sky Survey Deep Extragalactic Survey (UKIDSS DXS/J and K band), Spitzer Wise-area InfraRed Extragalactic survey (SWIRE/two mid-infrared bands), Canada France Hawaii Telescope (CFHT/z band), Issac Newton Telescope(INT/ u, g, r, i, z band) and Infrared Medium-deep Survey(IMS/J band).