Frequency translation via four-wave mixing Bragg scattering in Rb filled photonic bandgap fibers

Abstract

We demonstrate frequency translation at microwatt pump power levels in Rubidium vapor confined to a hollow-core photonic bandgap fiber using four-wave mixing Bragg scattering. The 5S(1/2)→5D(3/2) two-photon transition in 85Rb is employed for the four-wave mixing process. Using continuous-wave pump beams at 780 and 795 nm, a weak signal beam at 776 nm is translated to a wavelength of 762 nm with a 21% conversion efficiency at pump powers of 300 μW.

Continuous Generation of Rubidium Vapor in a Hollow Core Photonic Band-Gap Fiber

“…Such long operating times were achieved using vapor generation beams with substantially higher average powers and wavelengths close to the band edge of the PBGF. The generated OD's are commensurate with those required for all previous demonstrations of optical modulation using the Rb-PBGF system [11,12,15,17,18,23]. This capability greatly facilitates performing experiments related to weak nonlinearity-based quantum computing [24].…”

Continuous generation of rubidium vapor in hollow-core photonic bandgap fibers

“…Such long operating times were achieved using vapor generation beams with substantially higher average powers and wavelengths close to the band edge of the PBGF. The generated OD's are commensurate with those required for all previous demonstrations of optical modulation using the Rb-PBGF system [11,12,15,17,18,23]. This capability greatly facilitates performing experiments related to weak nonlinearity-based quantum computing [24].…”

“…The requirements for achieving such nonlinearities in atomic/molecular vapors are a high optical depth (OD) and small cross sectional area to achieve high intensities for low power levels [9]. Alkali metal vapors confined to hollow-core photonic band-gap fibers (PBGF) have extremely large optical nonlinearities [10][11][12][13][14], and large cross phase shifts [15,16], all optical amplitude modulation [17], frequency translation [18] and quantum memory [19] have been demonstrated using such systems. More recently, high OD's have been observed by loading cold atoms in a PBGF from a MOT [20] and the diffusive loading of a kagomé style PBGF with mercury vapor, capable of achieving high optical nonlinearities in the UV regime [21].…”

“…The Rb chamber design containing the PBGF is the same as that used previously [15,17,18,23]. A standard cleaning procedure for vacuum components was followed, after which we pre-baked the chamber for over a month to achieve ultrahigh vacuum (< 10 −9 Torr) before the Rb vapor was released.…”

Interference and nonlinear properties of four-wave-mixing resonances in thermal vapor: Analytical results and experimental verification

“…Atoms in diamond configuration have been successfully used as a nonlinear frequency conversion medium [10][11][12][13], applicable to light at single photon level. Both spectral [14,15] and temporal [16] properties of the diamond configuration have been studied.…”