نتایج جستجو برای: optical pumping

تعداد نتایج: 278457  

2009
B. H. McGuyer

We report a simple method to suppress the light shift in optical pumping systems. This method uses only frequency modulation of a radio frequency or microwave source, which is used to excite an atomic resonance, to simultaneously lock the source frequency to the atomic resonance and lock the pumping light frequency to suppress the light shift. We experimentally validate the method in a vapor-ce...

Journal: :Physical review letters 2007
Steven Hoekstra Joop J Gilijamse Boris Sartakov Nicolas Vanhaecke Ludwig Scharfenberg Sebastiaan Y T van de Meerakker Gerard Meijer

Optical pumping by blackbody radiation is a feature shared by all polar molecules and fundamentally limits the time that these molecules can be kept in a single quantum state in a trap. To demonstrate and quantify this, we have monitored the optical pumping of electrostatically trapped OH and OD radicals by room-temperature blackbody radiation. Transfer of these molecules to rotationally excite...

1999
H. Batelaan A. S. Green B. A. Hitt T. J. Gay

This paper reports the first experimental demonstration of an optically pumped electron spin filter. Unpolarized electrons produced in a cold-cathode discharge drift through a mixture of spin-polarized Rb and a nitrogen or helium buffer gas. Through spin-exchange collisions with the Rb, the drifting electrons become polarized along the optical pumping axis. We study the role of the buffer gas i...

Journal: :Optics express 2015
Weiqi Xue Luisa Ottaviano Yaohui Chen Elizaveta Semenova Yi Yu Alexandra Lupi Jesper Mork Kresten Yvind

We report a systematic study of thermal effects in photonic crystal membrane lasers based on line-defect cavities. Two material platforms, InGaAsP and InP, are investigated experimentally and numerically. Lasers with quantum dot layers embedded in an InP membrane exhibit lasing at room temperature under CW optical pumping, whereas InGaAsP membranes only lase under pulsed conditions. By varying ...

2015
Jonathan Breeze Ke-Jie Tan Benjamin Richards Juna Sathian Mark Oxborrow Neil McN Alford

Recently, the world's first room-temperature maser was demonstrated. The maser consisted of a sapphire ring housing a crystal of pentacene-doped p-terphenyl, pumped by a pulsed rhodamine-dye laser. Stimulated emission of microwaves was aided by the high quality factor and small magnetic mode volume of the maser cavity yet the peak optical pumping power was 1.4 kW. Here we report dramatic miniat...

2011
Cheng Bao Yao Elisee Kponou Yun Dong Zhang Jin Fang Wang Ping Yuan

Excited state lifetimes of C60/toluene solution and C60 films macromolecular were measured by pump-probe method. Relation between optical switching effect of material and pulse width of pumping field is briefly described. It is found that the faster switching speed of light is, the triplet state lifetime is shorter. A He-Ne laser, as a probe, passed through the sample in the pump-probe experime...

2014
Valentin V. Volchkov Tilman Pfau Jörg Wrachtrup

In this thesis, I study optical pumping as a powerful cooling tool for trapped ultra-cold atoms in a highly collisional regime. First application of optical pumping is a continuous loading scheme used to transfer atoms from a guided beam into a hybrid trap. Further, I introduce a Sisyphus cooling scheme based on radio-frequency transitions and optical pumping, operating simultaneously to the ac...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1390

any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

2013
Prashanth S. Venkataram

The Zeeman splittings of the hyperfine structure of rubidium as well as the ambient geomagnetic field are investigated by using an optical pumping apparatus. The frequencies of Zeeman transitions are proportional to the magnetic field applied; using this, the ambient geomagnetic field is found to be B = ((37.755±0.025)ex+(5.5179±0.0030)ey +(19.15±0.06st±0.67sy)ez) ·10−6 T, compared to an accept...

1994
P. Bouyer P. Lemonde M. Ben Dahan A. Michaud C. Salomon

We have investigated a new radiation pressure trap which relies on optical pumping and does not require any magnetic field. It employs six circularly polarized divergent beams and works on the red of a Jg −→ Je = Jg + 1 atomic transition with Jg ≥ 1/2. We have demonstrated this trap with cesium atoms from a vapour cell using the 852 nm Jg = 4 −→ Je = 5 resonance transition. The trap contained u...

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