IEEE Journal of Quantum Electronics

Passive Fraunhofer-wavelength atomic filter at 460.7 nm

Jerry A. Gelbwachs, Y. C. Chan

Published Jan 1, 1992• 15 citations

Abstract

A passive Fraunhofer-wavelength atomic filter in the spectral region of minimum seawater attenuation is reported. Signal light at 460.7 nm is strongly absorbed by strontium atoms contained in a heated vapor cell. Collisions with rare gases transfer population into the Sr(5p/sup 3/P/sub j/) level, which subsequently emits 689.3-nm photons. Up to 45% photon conversion efficiency was recorded. The strontium filter exhibits a 50- mu s decay time and a single noise passband.>

DOI: 10.1109/3.161316

Related papers

Passive Fraunhofer-wavelength atomic filter at 4227 nm

Jerry A. Gelbwachs, Yat C. Chan

We have demonstrated 25% internal photon conversion efficiency of a new passive atomic filter. The signal wavelength matches an intense Fraunhofer line at 422.7 nm, thereby offering enhanced sunlight rejection. A quasimolecular interaction promotes rapid energy transfer between the 4p (1)P(1) level and the 4p (3)P(J) level of neutral calcium for wavelength shifting of 422.7-nm light into 657.3-nm emission. We discuss augmentation of the photon conversion efficiency by radiation trapping.

Optics LettersMar 1, 199113 citations

A Fraunhofer-wavelength magnetooptic atomic filter at 422.7 nm

Yat C. Chan, Jerry A. Gelbwachs

A demonstration of the first magnetooptic atomic filter that overlays a strong solar Fraunhofer line is reported. Compared with alkali magnetooptic filters, this filter enjoys a large reduction in solar interference and a significant decrease in the number of noise passbands. The filter utilizes the strong Ca(4p/sup 1/P/sub 1/-4s/sup 1/S/sub 0/) transition at 422.7 nm. Under the weak magnetic field experimental conditions, a maximum transmission efficiency of 55% and a symmetrical double-peaked transmission spectrum with 1.5 GHz wide passbands were observed. The filter's frequency response was measured with a laser intensity modulation technique. No falloff was observed at 176 MHz, the highest frequency available with the apparatus. Calculations indicate that further improvements in filter performance can be achieved by optimizing the magnetic field and the cell temperature.>

IEEE Journal of Quantum ElectronicsJan 1, 199338 citations

Experimental demonstration of internal wavelength conversion in the magnesium atomic filter

Y. C. Chan, Martin D. Tabat, Jerry A. Gelbwachs

We describe what is to our knowledge the first experimental demonstration of internal wavelength conversion in the metastable Mg atomic filter. The filter operates at a Fraunhofer line, thereby offering intrinsic solar background rejection. Incoming green Fraunhofer photons (518 nm) are absorbed by metastable Mg atoms in an oven cell and are converted into UV (384-nm) photons. We observed a green-to-UV conversion efficiency of greater than 50%.

Optics LettersJul 15, 198919 citations

Proposed Fraunhofer-wavelength atomic filter at 5349 nm

Jerry A. Gelbwachs

A new atomic filter is proposed. It operates at 534.9 nm. The new filter offers two important advantages for openchannel laser communications. First, its wavelength matches the output of the frequency-doubled Nd:BEL laser. Second, the filter overlays a solar Fraunhofer line, thereby offering intrinsic sunlight suppression. Ultranarrowband optical filtering takes place within the singlet manifold of neutral-calcium vapor. Excellent filter properties are deduced from spectroscopic examination of the atomic system. A novel feature of the new filter is the potential for greater-than-unity internal photon conversion.

Optics LettersOct 15, 19907 citations

Laser-Induced Fluorescence in Thin and Dense Cs Atomic Vapors

Armen D. Sargsyan, David G. Sarkisyan

Laser-induced fluorescence (LIF) was studied in the 400–1000 nm wavelength range using narrow-band 852 nm laser radiation resonant with Cs atomic 6S1/2 → 6P3/2 transition. T-shaped cells made entirely of technical sapphire with thicknesses of L = 1 cm, 40 μm, and ~400 nm, containing cesium atomic vapor, were used. It was shown that with the cell thickness decrease (from centimeters to nanometer thicknesses), many LIF signals are suppressed due to an increase in the number of atomic collisions with the walls, leading to quenching of excited states. By recording the LIF signal, it is also possible to estimate the amount of residual Rb atomic vapor (if any exists) in the Cs-containing cell. The Cs vapor cell can serve as an efficient optical frequency converter filter and has other applications.

Journal of Contemporary Physics (Armenian Academy of Sciences)Jun 1, 20260 citations

Atomic resonance filters

Jerry A. Gelbwachs

The atomic resonance filter (ARF) is an ultranarrowband (Q approximately 10/sup 5/-10/sup 6/), large-acceptance-angle, isotropic optical filter. These features make the device ideally suited for applications in which weak laser signals are detected against a continuum background. The filter properties arise from the physical processes of absorption, emission, and internal energy conversion in atomic vapors. The characteristics of the ARF are described and the underlying physics that governs the operation is discussed. Representative examples of passive, active, and IR filters are presented. A metastable ARF that offers improved solar background-limited performance by filtering signals at Fraunhofer wavelengths is described.>

IEEE Journal of Quantum ElectronicsJul 1, 198888 citations