Observation of third-order intersubband dc Kerr effect at the midinfrared wavelengths in GaAs quantum wells

Abstract

We report on the first observation of third-order intersubband nonlinearities in a quantum well structure. We have measured the dc Kerr effect in a symmetric quantum well and found that the Kerr coefficients due to intersubband transitions are six orders of magnitude larger than that of bulk GaAs. To our best knowledge this is the largest value ever measured for the third-order susceptibility. By including dc screening effects and evaluating the internal electric field in the well, a good agreement between the calculated coefficients and the experimental ones was found.

Nonlinear optical rectification and optical absorption in GaAs–Ga1–xAlxAs asymmetric double quantum wells: Combined effects of applied electric and magnetic fields and hydrostatic pressure

“…These dipole moments are clear evidence that the large optical nonlinearities may be obtained in semiconductor QW structures. Indeed, very large second-order nonlinear optical properties associated with ISBT such as the second harmonic generation (SHG) [3], the nonlinear optical rectification [4], and frequency down conversion [5], and third-order nonlinear optical properties such as the dc Kerr effect [6], third harmonic generation (THG) [7], and four-wave mixing [8] have been observed experimentally. Following these experimental observations, many theoretical studies related to the optical nonlinearities have also been performed [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

Intersubband optical transitions in one dimensional quantum wire structures

“…ISBT in 2D quantum wells (QWs) have been found to have very large optical dipole matrix elements [4] since the transitions are between subbands of the same Bloch wavefunction while the corresponding envelope wavefunctions vary on scales of the order of the QW size. These transitions have been used to study a new class of infrared (IR) optical devices such as long-wavelength IR detectors [5], optical modulators [6], and nonlinear optical effects [7][8][9]. In this respect ISBT in QWR structures offer new features since the additional confinement of the charge carriers modifies the selection rules and the density of states associated with these transitions.…”

Intersubband optical absorption in a quantum well under a tilted magnetic field

“…In these studies large oscillator strength, fast relaxation times, and very large nonlinear optical coefficients are observed [2]. The tunability of the band gap makes it possible to optimize the QW structure for specific applications.…”

“…The tunability of the band gap makes it possible to optimize the QW structure for specific applications. Infrared detectors [3], modulators [2,4,5], and lasers [6] are examples of applications that make use of the novel properties associated with intersubband optical transitions. Recently, experimental studies of the intersubband absorption within the conduction band of a GaAs QW without an applied electric field have been reported [7].…”