Incoherent backward photon echo in ruby upon excitation through an optical fiber

Abstract

Abstract:The results of an experimental investigation of the incoherent photon echo in ruby (with Cr 3+ concentration equal to 0.16 wt%) at T = 1.7 K are presented. Optical fiber with length 3 m and diameter 100 µm was used for delivery of the first exciting pulse to a sample. The dependence of the IPE intensity on the excitation wavelength within the width of R1 absorption line was studied. The IPE decay curve was obtained and the phase relaxation time was found to be equal to 98 ns. Oscillogram of incoherent backward photon echo (IPE) in concentrated ruby. The IPE signal is the first one at the right. The other pulses are the signals of diffraction corresponding to the first and the second exciting laser pulses

Photon echo in ruby doped only by53Cr isotope ions

“…The analysis shows that these beats are due to the hyperfine interaction of the valence electrons of 53 Cr isotope ions with their nuclei. This conclusion agrees with the results of experiment [6]. The special attention was paid to the investigation of the kinetics of SPE decay in zero magnetic field.…”

Understanding of Collective Atom Phase Control in Modified Photon Echoes for a Near-Perfect Storage Time-Extended Quantum Memory

“…To make the first echo (E 1 ) silent to avoid affecting the final echo (E 2 ), both rephasing pulse propagation directions were set to be opposite (backward) to that of the D pulse [10]. To satisfy the backward photon echo condition, the control pulses were set to counter-propagate each other [19]:…”

“…Over the last decade, modified photon echo techniques have been intensively studied and applied to quantum memory applications to overcome the fundamental limitation of population inversion in conventional photon echoes, for which the population inversion excited by an optical π pulse results in quantum noises caused by spontaneous and/or stimulated emissions [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Photon echo has also been experimentally studied in a highly doped crystal Tm:YAG [ 18 ] and in ruby upon excitation through an optical fiber [ 19 ]. Although some of these techniques have been successful for quantum state storage and retrieval [ 8 , 9 , 10 , 11 , 12 , 13 ], the understanding of collective atom phase control is still limited, where absorptive photon echoes have been involved in controlled atomic frequency comb (AFC) echoes [ 8 , 9 ] and doubly rephased (DR) photon echoes [ 10 , 11 , 12 , 13 ].…”

“…The data (D), the first rephasing (R 1 ) and the second rephasing (R 2 ) pulses were resonant to the transition of to satisfy the requirements of the DR photon echo scheme [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. The control pulses, C 1 and C 2 , were resonant between states and to enable CCC [ 14 , 15 , 16 , 17 , 18 , 19 ]. Initially, all atoms of the medium were in the ground state, .…”

“…To make the first echo (E 1 ) silent to avoid affecting the final echo (E 2 ), both rephasing pulse propagation directions were set to be opposite (backward) to that of the D pulse [ 10 ]. To satisfy the backward photon echo condition, the control pulses were set to counter-propagate each other [ 19 ]: ; each pulse j was characterized by a wave vector . Unlike phase mismatching in silent echo (E 1 ) formation [ 10 ], which is determined by D and R 1 , the final echo (E 2 ) propagation direction ( ) is determined by the control pulses [ 14 ].…”