Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Letters

Ultrashort-pulse-controlled all-optical modulation by interband and intersubband transitions in doped quantum wells

Arup Neogi, Osamu Wada, Yutaka Takahashi, Hitoshi Kawaguchi

Published Aug 1, 1998• 10 citations
Publisher

Abstract

The optimum condition for achieving highly efficient ultrafast all-optical pulse modulation by modification of the absorption of a pulsed interband light field by ultrasubband control-light pulses in a doped quantum well is investigated. The modulation efficiency in the femtosecond domain can be maximized by an intersubband control light with a pulse width (200 fs) that is comparable with the phase-relaxation time of the system and an intensity that is close to the intersubband saturation intensity.

DOI
10.1364/ol.23.001212

Related papers

Ultrafast all-optical modulation of interband-light pulses by ultrashort intersubband light pulses in semiconductor quantum wells

Anirban Neogi, H. Yoshida, Teruo Mozume +1 more

We analyze the optical modulation of an interband resonant light pulse by intersubband resonant light pulses in a three-level quantum well system. The origin of the third order self-saturation optical nonlinearity resulting in the modification of the interband light absorption is assumed to lie in the carrier density modulation induced by the interband and intersubband transitions. The optical nonlinearity can be optimized to achieve the maximum modulation by applying control light pulses shorter than the intersubband energy relaxation time but longer than the intersubband phase relaxation time. We have also experimentally investigated the material system suitable for optical communication regime and have observed that the In0.53Ga0.47As/AlAs0.56Sb0.44 quantum well lattice matched to InP yielding an intersubband transition as short as 1.4 μm is the most suitable system for the proposed modulation scheme.

Journal of Applied Physics•Mar 15, 1999•13 citations

Efficient All-Optical Interband Light Modulation by Ultrafast Manipulation of Intersubband Transitions in an Asymmetric Quantum Well*

Arup Neogi, Haruhiko Yoshida, Teruo Mozume +1 more

An efficient modulation scheme at relatively lower control light intensities is proposed using ultrashort interband and intersubband-resonant coupling light pulses in a novel asymmetric In x Ga1-x As/AlAs semiconductor quantum well structure. The shape of the intersubband-control light pulses can manipulate the interband-signal light pulse absorption. The carrier relaxation rate of the quantum well system can be estimated from the interband nonlinear optical parameters induced by the intersubband control light field. The modulation efficiency in the proposed structure is twice than in a conventional symmetric quantum well structure. This reduces the threshold optical energy below 1 pJ in a 100-µm2 waveguide structure on using 500 fs control light pulses owing to the enhanced optical nonlinearities in the proposed structure.

Japanese Journal of Applied Physics•Feb 1, 1999•4 citations

Analysis of transient interband light modulation by ultrashort intersubband resonant light pulses in semiconductor quantum wells

Arup Neogi, Yutaka Takahashi, Hitoshi Kawaguchi

We explore the transient characteristics of an interband resonant light modulation process by ultrashort intersubband resonant light pulses in semiconductor quantum wells (QW's). The modulation characteristics in a three-level semiconductor QW system, including the effects due to in-plane momentum, have been investigated by a numerical analysis of the coupled Bloch equations using a density-matrix approach. We have studied the effect of the carrier density and the nature of the intersubband coupling light on the transient absorption features of the interband light. The modulation process has been compared in doped and undoped QW's. The switching behavior of the strong interband light field in presence of a train of intersubband light pulses has also been discussed.

IEEE Journal of Quantum Electronics•Jan 1, 1997•13 citations

All-optical modulation using an n-doped quantum-well structure

Susumu Noda, Tetsuya Uemura, Takao Yamashita +1 more

The modulation of interband-resonant light by intersubband-resonant light using an n-doped quantum well is proposed, and results of the theoretical analysis are reported. It is shown that a large change in absorption coefficient from 100 to 3160 cm−1 for interband-resonant light can be obtained by changing the intensity of intersubband-resonant light from 0 to 1 MW/cm2. Very fast modulation speed (∼ps) can be expected.

Journal of Applied Physics•Dec 15, 1990•83 citations

Interband-resonant light modulation by intersubband-resonant light in undoped quantum wells

Susumu Noda, Masaki Ohya, T. Sakamoto +1 more

Interband-resonant light modulation by intersubband-resonant light in undoped quantum wells is investigated. Theoretical calculation for the modulation is carried out by considering not only the excitonic interband-transition but also the continuous level transition between the conduction and valence bands. The modulation characteristics are compared with those of the modulation using n-doped quantum wells. The possibility of the modulation using undoped quantum well is successfully shown by real-time single-shot experiment using Ti-Al/sub 2/O/sub 3/ and CO/sub 2/ lasers for interband- and intersubband-resonant lights at room temperature.

IEEE Journal of Quantum Electronics•Mar 1, 1996•15 citations

Nonlinear intersubband optical absorptions in a multiple quantum wells with an applied electric field

Wang Weizhong, P. Denney, I. Miyamoto +1 more

In multiple quantum wells system, a large dipole strength and a narrow band width were observed. This suggests that the intersubband optical transitions in a quantum well may have very large optical nonlinearities. The intersubband transition have potential for device applications in far-infrared laser amplifiers, photodetectors and high-speed electrooptical modulators. In device design, the region of input optical density for linear response is a very important parameter. And the optical saturation is related with tunnelling effects and the intersubband relaxations. So the intersubband nonlinear absorption is very valuble for a fundamental and a practical point of views. Recently, there are some works on this region [1], [2].

International Congress on Applications of Lasers & Electro-Optics (ICALEO)•Oct 1, 1993•0 citations
The optimum condition for achieving highly efficient ultrafast all-optical pulse modulation by modification of the absorption of a pulsed interband light field by ultrasubband control-light pulses in a doped quantum well is investigated. The modulation efficiency in the femtosecond domain can be maximized by an intersubband control light with a pulse width (200 fs) that is comparable with the phase-relaxation time of the system and an intensity that is close to the intersubband saturation intensity.
We analyze the optical modulation of an interband resonant light pulse by intersubband resonant light pulses in a three-level quantum well system. The origin of the third order self-saturation optical nonlinearity resulting in the modification of the interband light absorption is assumed to lie in the carrier density modulation induced by the interband and intersubband transitions. The optical nonlinearity can be optimized to achieve the maximum modulation by applying control light pulses shorter than the intersubband energy relaxation time but longer than the intersubband phase relaxation time. We have also experimentally investigated the material system suitable for optical communication regime and have observed that the In0.53Ga0.47As/AlAs0.56Sb0.44 quantum well lattice matched to InP yielding an intersubband transition as short as 1.4 μm is the most suitable system for the proposed modulation scheme.
An efficient modulation scheme at relatively lower control light intensities is proposed using ultrashort interband and intersubband-resonant coupling light pulses in a novel asymmetric In x Ga1-x As/AlAs semiconductor quantum well structure. The shape of the intersubband-control light pulses can manipulate the interband-signal light pulse absorption. The carrier relaxation rate of the quantum well system can be estimated from the interband nonlinear optical parameters induced by the intersubband control light field. The modulation efficiency in the proposed structure is twice than in a conventional symmetric quantum well structure. This reduces the threshold optical energy below 1 pJ in a 100-µm2 waveguide structure on using 500 fs control light pulses owing to the enhanced optical nonlinearities in the proposed structure.
We explore the transient characteristics of an interband resonant light modulation process by ultrashort intersubband resonant light pulses in semiconductor quantum wells (QW's). The modulation characteristics in a three-level semiconductor QW system, including the effects due to in-plane momentum, have been investigated by a numerical analysis of the coupled Bloch equations using a density-matrix approach. We have studied the effect of the carrier density and the nature of the intersubband coupling light on the transient absorption features of the interband light. The modulation process has been compared in doped and undoped QW's. The switching behavior of the strong interband light field in presence of a train of intersubband light pulses has also been discussed.
Interband-resonant light modulation by intersubband-resonant light in undoped quantum wells is investigated. Theoretical calculation for the modulation is carried out by considering not only the excitonic interband-transition but also the continuous level transition between the conduction and valence bands. The modulation characteristics are compared with those of the modulation using n-doped quantum wells. The possibility of the modulation using undoped quantum well is successfully shown by real-time single-shot experiment using Ti-Al/sub 2/O/sub 3/ and CO/sub 2/ lasers for interband- and intersubband-resonant lights at room temperature.
In multiple quantum wells system, a large dipole strength and a narrow band width were observed. This suggests that the intersubband optical transitions in a quantum well may have very large optical nonlinearities. The intersubband transition have potential for device applications in far-infrared laser amplifiers, photodetectors and high-speed electrooptical modulators. In device design, the region of input optical density for linear response is a very important parameter. And the optical saturation is related with tunnelling effects and the intersubband relaxations. So the intersubband nonlinear absorption is very valuble for a fundamental and a practical point of views. Recently, there are some works on this region [1], [2].