• Title/Summary/Keyword: cesium atom

Search Result 5, Processing Time 0.022 seconds

Optimization of Diode-pumped Cesium Vapor Laser Using Frequency Locked Pump Laser

  • Hong, Seongjin;Kong, Byungjoo;Lee, Yong Soo;Oh, Kyunghwan
    • Current Optics and Photonics
    • /
    • v.2 no.5
    • /
    • pp.443-447
    • /
    • 2018
  • We propose a diode-pumped cesium laser using frequency locking of a pump laser that can effectively increase the maximum output power of the cesium laser. We simultaneously monitored the absorption spectrum of cesium and the laser output power, and the frequency of pump laser was locked at the center of the $D_2$ absorption line of the cesium atom to obtain an effective gain enhancement. Using this scheme, we have achieved output power increase of ~0.1 W compared to when frequency locking was not applied. Furthermore, by optimizing the temperature of the cesium cell and the reflectivity of the output coupler, we successfully achieved an output power of 1.4 W using the pump power of 2.9 W, providing a slope efficiency of 61.5% and optical-to-optical efficiency of 49%.

Crystal Structure of Dehydrated Partially Ag$^+$-Exchanged Zeolite A treated with Cesium Vapor at 250${^{\circ}C}$

  • Kim, Duk-Soo;Song, Seong-Hwan;Kim, Yang
    • Bulletin of the Korean Chemical Society
    • /
    • v.10 no.3
    • /
    • pp.234-238
    • /
    • 1989
  • The crystal structure of partially $Ag^+$-exchanged zeolite A, $Ag_{3.2}Na_{8.8}$-A, vacuum dehydrated at $360^{\circ}C$ and then exposed to 0.1 torr of cesium vapor for 12 hours at $250^{\circ}C$ has been determined by single-crystal X-ray diffraction techniques in the cubic space group Pm3m (a = 12.262(2)${\AA})\;at\;21(1)^{\circ}C$. The structure was refined to the final error indexes $R_1=0.068\;and\;R_2=0.072$ by using 338 reflections for which $I_o\;>\;3{\sigma}(I_o)$ and the composition of unit cell is $Ag_{3.2}Cs_{8.8}-A.\;3\;Cs^+$ ions lie on the centers of the 8-rings at sites of D4h symmetry. Two crystallographycally different 6-ring $Cs^+$ ions were found: 1.5 $Cs^+$ ions at Cs(2) are located inside of sodalite cavity and 4.3 $Cs^+$ ions at Cs(3) are located in the large cavity. The fractional occupancies observed at Cs(2) and Cs(3) indicate that the existence of at least three types of unit cells with regard to the 6-ring $Cs^+$ ions. For example, 50% of unit cells may have two $Cs^+$ ions at Cs(2) and 4 $Cs^+$ ions at Cs(3). 30% of unit cells may have one Cs+ ion at Cs(2) and 5 $Cs^+$ ions at Cs(3). The remaining 20% would have one $Cs^+$ ion at Cs(2) and 4 $Cs^+$ ions at Cs(3). On threefold axes of the unit cell two non-equivalent Ag atom positions are found in the large cavity, each containing 0.64 and 1.92 Ag atoms, respectively. A crystallographic analysis may be interpreted to indicate that 0.64 $(Ag_5)^+$ clusters are present in each large cavity. This cluster may be viewed as a tetrasilver molecule $(Ag_4)^0$(bond length, 2.84${\AA}$) stabilized by the coordination of one $Ag^+$ ion.

Characteristics of two extended-cavity diode lasers phase-locked with a 9.2 CHz frequency offset (9.2 GHz 주파수 차이로 위상잠금된 두 외부 공진기 다이오드 레이저의 제작 및 특성 조사)

  • Kwon, Taek-Yong;Shin, Eun-Ju;Yoo, Dae-Hyuk;Lee, Ho-Sung;In, Min-Kyo;Cho, Hyuk;Park, Sang-Eon
    • Korean Journal of Optics and Photonics
    • /
    • v.13 no.6
    • /
    • pp.543-547
    • /
    • 2002
  • We have constructed two extended-cavity diode lasers which are phase-locked with a 9.2 GHz frequency offset. We adopted a digital servo circuit for the phase-locking. The relative linewidth of the phase-locked lasers was less than 2 Hz. Using the measured beat spectrum, we found the carrier concentration to be about 93 %. We measured phase noise and relative frequency stability of the lasers. The Allan deviation at the gate time of 20 s was $2.7{\times}10^{-19}$.