Carrier relaxation dynamics in an ultrafast all-optical modulator using an intersubband transition

Asano, T.; Yoshizawa, S.; Noda, S.
December 2001
Applied Physics Letters;12/31/2001, Vol. 79 Issue 27, p4509
Academic Journal
An improvement of an all-optical modulation scheme that utilizes an intersubband transition is proposed and investigated in connection with intersubband carrier relaxation dynamics. N-doped GaAs/AlGaAs quantum wells are pumped by an ultrashort (∼120 fs) intersubband-resonant pulse and probed by an interband-resonant white-light continuum. Ultrafast modulation speed of ∼0.4 ps is demonstrated, which is faster than that of the previous scheme by as much as a factor of 10. It is found that a large part of the carriers, which are excited from the first conduction subband to the second conduction subband, transfer to unknown trapping states at a relaxation time that is comparable to that of the pump–pulse duration. The existence of the carrier relaxation path via L valley subbands is strongly suggested as the cause. © 2001 American Institute of Physics.


Related Articles

  • Preselection boosts U.K. voice market. Scales, Ian // America's Network;4/15/2003, Vol. 107 Issue 6, p19 

    Focuses on the impact of using carrier preselection system on the performance of telecommunication industry in the U.S. Ability of the customers to specify their carriers across the network without using codes; Use of the system to take a serious crack at residential and business voice...

  • Carrier dynamics in staggered-band lineup n-InAlAs/n-InP heterostructures. Bohrer, J.; Krost, A. // Applied Physics Letters;4/11/1994, Vol. 64 Issue 15, p1992 

    Examines the carrier dynamics in staggered-band lineup n-InAlAs/n-InP heterostructures. Temperature and time dependence of the spatially indirect recombination of two dimensional electrons and localized holes; Effect of temperature increase on photoluminescence intensity and decay time...

  • Circuit compensates optocoupler temperature coefficient. Zias, J Micheal // EDN;11/22/2001, Vol. 46 Issue 26, p93 

    Focuses on circuit compensates optocoupler temperature coefficient. Consideration in the use of optocoupler; Use of two optocouplers; Illustration on two optocouplers; Theory of control-system feedback.

  • CLEC data expansion.  // Communications News;Aug99, Vol. 36 Issue 8, p8 

    Highlights the 1999 Annual Competitive Local Exchange Carrier (CLEC) Report. Predicted growth for the Internet and other high-speed data services; Dominant service of the CLEC industry; How the carriers positioned themselves to rule the data market.

  • Comment on ‘‘Noncontact doping level determination in GaAs using photoreflectance spectroscopy’’ [J. Appl. Phys. 62, 4558 (1987)]. Bottka, N.; Gaskill, D. K. // Journal of Applied Physics;10/15/1988, Vol. 64 Issue 8, p4243 

    Presents information on a study which analyzed the use of Franz-Keldysh oscillations (FKO) to determine the carrier concentration of the material. Invariance of the electroreflectance with the applied direct current voltage; Spacing of the FKO scale; Use of the FKO to determine the doping...

  • Rail-safe technology.  // Transportation & Distribution;Nov98, Vol. 38 Issue 11, p20 

    States that a positive train control (PTC) system is being developed by Conrail, Norfolk Southern, CSX rail companies and Rockwell Transportation Electronics. Cost of the project; Who is funding the project; Description of PTC; Plans made by Rockwell for the system.

  • Weighing the Cost of Reweighs. Barrett, Colin // Traffic World;11/26/2007, Vol. 271 Issue 47, p38 

    The article provides an answer to a question on how to start the legal action to stop the misleading custom and reimburse carrier's ill-got-ten gains.

  • The New AUTOMATION Part 2. Walker, Gerald M. // World Broadcast Engineering;Jul/Aug2001, Vol. 24 Issue 7, p24 

    Focuses on the ideal control system in a broadcast environment. Definition of a control system; Guide for implementing a networked control system containing user interface, system logic, data, communication and equipment drivers; Components of system attributes.

  • Measurement of radiative, Auger, and nonradiative currents in 1.3-μm InGaAsP buried heterostructure lasers. Olshansky, Robert; LaCourse, Joanne; Chow, Terrance; Powazinik, William // Applied Physics Letters;2/9/1987, Vol. 50 Issue 6, p310 

    Frequency response measurements are used to determine the carrier lifetime of 1.3-μm InGaAsP buried heterostructure lasers between 1 mA and threshold. The data confirm previous results on the radiative and Auger recombination coefficients and reveal the presence of a nonradiative current...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics