The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform

Mike Hettich - One of the best experts on this subject based on the ideXlab platform.

  • all optical control of comb like coherent acoustic phonons in multiple quantum well structures through double pump pulse pump probe experiments
    Optics Express, 2019
    Co-Authors: V Gusev, Thomas Dekorsy, Mike Hettich
    Abstract:

    We present an advancement in applications of ultrafast optics in picosecond laser ultrasonics - laser-induced comb-like coherent acoustic phonons are optically controlled in a In0.27Ga0.73As/GaAs multiple quantum well (MQW) structure by a high-speed asynchronous optical sampling (ASOPS) system based on two GHz Yb:KYW lasers. Two successive pulses from the same pump laser are used to excite the MQW structure. The second pump light pulse has a tunable time delay with respect to the first one and can be also tuned in intensity, which enables the amplitude and phase modulation of acoustic phonons. This yields rich temporal acoustic patterns with suppressed or enhanced amplitudes, various wave-packet shapes, varied wave-packet widths, reduced wave-packet periods and varied phase shifts of single-period oscillations within a wave-packet. In the Frequency domain, the amplitude and phase shift of the individual comb Component present a second-pump-delay-dependent cosine-wave-like and sawtooth-wave-like variation, respectively, with a modulation Frequency equal to the comb Component Frequency itself. The variations of the individual Component amplitude and phase shift by tuning the second pump intensity exhibit an amplitude valley and an abrupt phase jump at the ratio around 1:1 of the two pump pulse intensities for certain time delays. A simplified model, where both generation and detection functions are assumed as a cosine stress wave enveloped by Gaussian or rectangular shapes in an infinite periodic MQW structure, is developed in order to interpret acoustic manipulation in the MQW sample. The modelling agrees well with the experiment in a wide range of time delays and intensity ratios. Moreover, by applying a heuristic-analytical approach and nonlinear corrections, the improved calculations reach an excellent agreement with experimental results and thus enable to predict and synthesize coherent acoustic wave patterns in MQW structures.

Ashwin A Seshia - One of the best experts on this subject based on the ideXlab platform.

  • excitation of coupled phononic Frequency combs via two mode parametric three wave mixing
    Physical Review B, 2018
    Co-Authors: Adarsh Ganesan, Cuong Do, Ashwin A Seshia
    Abstract:

    This paper builds on the recent demonstration of three-wave mixing based phononic Frequency comb. Here, in this process, an intrinsic coupling between the drive and resonant Frequency leads to a Frequency comb of spacing corresponding to the separation between drive and resonant Frequency. In this paper, through the coupling with other identical devices, we demonstrate the emergence of two different Frequency comb regimes using a single tone external drive signal. Several interesting features for coupled Frequency combs are identified, including the following: (1) the spacing of the Component Frequency combs are controlled by two different resonant frequencies, each associated with two different modes; (2) the nonlinear drive level dependence is different for the Component Frequency combs; (3) mutually exclusive well-bounded regimes for each Component Frequency comb exist, and such regimes are not merely described by well-known parametric resonance thresholds.

  • excitation of coupled phononic Frequency combs via two mode parametric three wave mixing
    Physical Review B, 2018
    Co-Authors: Adarsh Ganesan, Cuong Do, Ashwin A Seshia
    Abstract:

    © 2018 American Physical Society. This paper builds on the recent demonstration of three-wave mixing based phononic Frequency comb. Here, in this process, an intrinsic coupling between the drive and resonant Frequency leads to a Frequency comb of spacing corresponding to the separation between drive and resonant Frequency. In this paper, through the coupling with other identical devices, we demonstrate the emergence of two different Frequency comb regimes using a single tone external drive signal. Several interesting features for coupled Frequency combs are identified, including the following: (1) the spacing of the Component Frequency combs are controlled by two different resonant frequencies, each associated with two different modes; (2) the nonlinear drive level dependence is different for the Component Frequency combs; (3) mutually exclusive well-bounded regimes for each Component Frequency comb exist, and such regimes are not merely described by well-known parametric resonance thresholds.

V Gusev - One of the best experts on this subject based on the ideXlab platform.

  • all optical control of comb like coherent acoustic phonons in multiple quantum well structures through double pump pulse pump probe experiments
    Optics Express, 2019
    Co-Authors: V Gusev, Thomas Dekorsy, Mike Hettich
    Abstract:

    We present an advancement in applications of ultrafast optics in picosecond laser ultrasonics - laser-induced comb-like coherent acoustic phonons are optically controlled in a In0.27Ga0.73As/GaAs multiple quantum well (MQW) structure by a high-speed asynchronous optical sampling (ASOPS) system based on two GHz Yb:KYW lasers. Two successive pulses from the same pump laser are used to excite the MQW structure. The second pump light pulse has a tunable time delay with respect to the first one and can be also tuned in intensity, which enables the amplitude and phase modulation of acoustic phonons. This yields rich temporal acoustic patterns with suppressed or enhanced amplitudes, various wave-packet shapes, varied wave-packet widths, reduced wave-packet periods and varied phase shifts of single-period oscillations within a wave-packet. In the Frequency domain, the amplitude and phase shift of the individual comb Component present a second-pump-delay-dependent cosine-wave-like and sawtooth-wave-like variation, respectively, with a modulation Frequency equal to the comb Component Frequency itself. The variations of the individual Component amplitude and phase shift by tuning the second pump intensity exhibit an amplitude valley and an abrupt phase jump at the ratio around 1:1 of the two pump pulse intensities for certain time delays. A simplified model, where both generation and detection functions are assumed as a cosine stress wave enveloped by Gaussian or rectangular shapes in an infinite periodic MQW structure, is developed in order to interpret acoustic manipulation in the MQW sample. The modelling agrees well with the experiment in a wide range of time delays and intensity ratios. Moreover, by applying a heuristic-analytical approach and nonlinear corrections, the improved calculations reach an excellent agreement with experimental results and thus enable to predict and synthesize coherent acoustic wave patterns in MQW structures.

Adarsh Ganesan - One of the best experts on this subject based on the ideXlab platform.

  • excitation of coupled phononic Frequency combs via two mode parametric three wave mixing
    Physical Review B, 2018
    Co-Authors: Adarsh Ganesan, Cuong Do, Ashwin A Seshia
    Abstract:

    This paper builds on the recent demonstration of three-wave mixing based phononic Frequency comb. Here, in this process, an intrinsic coupling between the drive and resonant Frequency leads to a Frequency comb of spacing corresponding to the separation between drive and resonant Frequency. In this paper, through the coupling with other identical devices, we demonstrate the emergence of two different Frequency comb regimes using a single tone external drive signal. Several interesting features for coupled Frequency combs are identified, including the following: (1) the spacing of the Component Frequency combs are controlled by two different resonant frequencies, each associated with two different modes; (2) the nonlinear drive level dependence is different for the Component Frequency combs; (3) mutually exclusive well-bounded regimes for each Component Frequency comb exist, and such regimes are not merely described by well-known parametric resonance thresholds.

  • excitation of coupled phononic Frequency combs via two mode parametric three wave mixing
    Physical Review B, 2018
    Co-Authors: Adarsh Ganesan, Cuong Do, Ashwin A Seshia
    Abstract:

    © 2018 American Physical Society. This paper builds on the recent demonstration of three-wave mixing based phononic Frequency comb. Here, in this process, an intrinsic coupling between the drive and resonant Frequency leads to a Frequency comb of spacing corresponding to the separation between drive and resonant Frequency. In this paper, through the coupling with other identical devices, we demonstrate the emergence of two different Frequency comb regimes using a single tone external drive signal. Several interesting features for coupled Frequency combs are identified, including the following: (1) the spacing of the Component Frequency combs are controlled by two different resonant frequencies, each associated with two different modes; (2) the nonlinear drive level dependence is different for the Component Frequency combs; (3) mutually exclusive well-bounded regimes for each Component Frequency comb exist, and such regimes are not merely described by well-known parametric resonance thresholds.

Thomas Dekorsy - One of the best experts on this subject based on the ideXlab platform.

  • all optical control of comb like coherent acoustic phonons in multiple quantum well structures through double pump pulse pump probe experiments
    Optics Express, 2019
    Co-Authors: V Gusev, Thomas Dekorsy, Mike Hettich
    Abstract:

    We present an advancement in applications of ultrafast optics in picosecond laser ultrasonics - laser-induced comb-like coherent acoustic phonons are optically controlled in a In0.27Ga0.73As/GaAs multiple quantum well (MQW) structure by a high-speed asynchronous optical sampling (ASOPS) system based on two GHz Yb:KYW lasers. Two successive pulses from the same pump laser are used to excite the MQW structure. The second pump light pulse has a tunable time delay with respect to the first one and can be also tuned in intensity, which enables the amplitude and phase modulation of acoustic phonons. This yields rich temporal acoustic patterns with suppressed or enhanced amplitudes, various wave-packet shapes, varied wave-packet widths, reduced wave-packet periods and varied phase shifts of single-period oscillations within a wave-packet. In the Frequency domain, the amplitude and phase shift of the individual comb Component present a second-pump-delay-dependent cosine-wave-like and sawtooth-wave-like variation, respectively, with a modulation Frequency equal to the comb Component Frequency itself. The variations of the individual Component amplitude and phase shift by tuning the second pump intensity exhibit an amplitude valley and an abrupt phase jump at the ratio around 1:1 of the two pump pulse intensities for certain time delays. A simplified model, where both generation and detection functions are assumed as a cosine stress wave enveloped by Gaussian or rectangular shapes in an infinite periodic MQW structure, is developed in order to interpret acoustic manipulation in the MQW sample. The modelling agrees well with the experiment in a wide range of time delays and intensity ratios. Moreover, by applying a heuristic-analytical approach and nonlinear corrections, the improved calculations reach an excellent agreement with experimental results and thus enable to predict and synthesize coherent acoustic wave patterns in MQW structures.