Chirping of an Optical Transition by an Ultrafast Acoustic Soliton Train in a Semiconductor Quantum Well

Abstract

Acoustic solitons formed during the propagation of a picosecond strain pulse in a GaAs crystal with a ZnSe/ZnMgSSe quantum well on top lead to exciton resonance energy shifts of up to 10 meV, and ultrafast frequency modulation, i.e., chirping, of the exciton transition. The effects are well described by a theoretical analysis based on the Korteweg-de Vries equation and accounting for the properties of the excitons in the quantum well.

Optical and photocurrent spectroscopy with picosecond strain pulses

“…The ultrafast piezospectroscopic effect observed in the experiments with picosecond strain pulses opens a new field in optical and photocurrent spectroscopy [10,[13][14][15][16][17]. There the energy of resonant optical transitions is modulated on a picosecond timescale and the amplitude of this modulation exceeds the width of spectral lines in stationary experiments.…”

“…Recently efforts have been undertaken to merge the fields of ultrafast optics and acoustics, resulting in a variety of novel acousto-optic phenomena. Among them are the generation of THz radiation by acoustic waves [9] and strain pulse induced chirping of an optical transition [10].…”

Acoustic solitons: A robust tool to investigate the generation and detection of ultrafast acoustic waves

“…Solitons shorter than 200 fs with strain amplitude above 10 −3 have been inferred from experimental observations in MgO [3] and Al 2 O 3 [6] and could be useful to achieve carrier manipulation [9][10][11] or magnetic switching [12][13][14]. However, the absorbed optical power can raise the temperature of the sample so much that the attenuation is not negligible anymore.…”

Magnetization precession induced by quasitransverse picosecond strain pulses in (311) ferromagnetic (Ga,Mn)As

“…4 for the QTA (a) and QLA (b) modes. The temporal evolution of [19,25]. For shear waves corresponding studies have not…”

“…The experiments are performed in a cryostat with a superconducting magnet at temperature T = 6 K, well below the Curie temperature The picosecond strain pulses were generated by pulsed optical pump excitation of a 100 nm Al film deposited on the GaAs substrate, opposite to the (Ga,Mn)As layer. The temporal evolution of the strain pulses was described in earlier works [17][18][19] …”