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

Physical Review Letters

Ultrabroadband amplitude squeezing in a semiconductor laser

Susumu Machida, Y. Yamamoto

Published Feb 29, 1988• 123 citations
Publisher

Abstract

A constant-current--driven semiconductor laser produced a field with amplitude noise reduced to below the standard quantum limit by -1.7 dB (32%) over an entire frequency range from near dc to 1.1 GHz. The amplitude squeezing dependence on laser pump rate and optical loss was in good agreement with theoretical prediction. The new squeezed-state generation principle of high impedance suppression for pump-amplitude fluctuation was thus confirmed experimentally.

DOI
10.1103/physrevlett.60.792

Related papers

Observation of amplitude squeezing in a constant-current–driven semiconductor laser

S. Machida, Y. Yamamoto, Y. Itaya

Electromagnetic fields with photon-number fluctuation reduced below the standard quantum limit have been generated in a constant-current--driven semiconductor laser. The generation is based on a new principle of high impedance suppression for pump-amplitude fluctuation in a highly saturated laser oscillator. The observed noise level is 7.3% (31% after correction for detection quantum efficiency) in power below the standard quantum limit in the entire frequency range between 350 and 450 MHz.

Physical Review Letters•Mar 9, 1987•388 citations

High-impedance suppression of pump fluctuation and amplitude squeezing in semiconductor lasers

Y. Yamamoto, S. Machida

The pump amplitude fluctuation of a current-driven semiconductor laser can be suppressed to below the ordinary shot-noise level by ``high-impedance suppression.'' As a result of this pump-fluctuation suppression, the output of a current-driven semiconductor laser exhibits amplitude squeezing in the frequency region below the cavity bandwidth. The noise equivalent circuits and the quantum-mechanical Langevin equations are derived and discussed for clarifying the difference between an ordinary laser oscillator with shot-noise-limited pump fluctuation and a constant-current-driven semiconductor laser.

Physical Review A•Jun 1, 1987•169 citations

Squeezing in an injection-locked semiconductor laser

Shuichiro Inoue, S. Machida, Y. Yamamoto +1 more

The intensity-noise properties of an injection-locked semiconductor laser were studied experimentally. The constant-current-driven semiconductor laser producing the amplitude-squeezed state whose intensity noise was reduced below the standard quantum limit (SQL) by 0.72 dB was injection-locked by an external master laser. The measured intensity-noise level of the injection-locked semiconductor laser was 0.91 dB below the SQL. This experimental result indicates that a phase-coherent amplitude-squeezed state or squeezed vacuum state together with a reference local oscillator wave can be generated directly by semiconductor laser systems.

Physical Review A•Sep 1, 1993•37 citations

Amplitude squeezing in a semiconductor laser using quantum nondemolition measurement and negative feedback

Y. Yamamoto, N. Imoto, S. Machida

A new scheme for generating an amplitude-squeezed state is proposed. The photon-flux fluctuation of a semiconductor-laser output wave is measured with a quantum nondemolition (QND) detector, and is negatively fed back to the laser pumping current. The operator Langevin equations are derived by combining the quantum-mechanical analyses on the laser internal-external field fluctuations, the quantum nondemolition detector based on an optical Kerr effect, and a negative-feedback circuit. The output wave features a reduced photon number noise below the standard quantum limit, 〈(\ensuremath{\Delta}n^${)}^{2}$〉^〉, and an enhanced phase noise above that, 〈(\ensuremath{\Delta}\ensuremath{\psi}^${)}^{2}$〉>(1/4)〈n^${〉}^{\mathrm{\ensuremath{-}}1}$, while the minimum uncertainty product is still preserved. The observed photoelectron statistics in a negative-feedback GaAs laser diode using a conventional p-i-n photodiode (not a QND detector) are shown to exhibit sub-Poissonian statistics with the variance 〈(\ensuremath{\Delta}n^${)}^{2}$〉apeq20.26〈n^〉. The measured photocurrent fluctuation spectral density is also indicated to be below the standard quantum limit by a factor of 0.2 (=-7 dB). The experimental results also confirm that such amplitude squeezing is only observed inside the feedback loop and cannot be extracted from the loop unless a quantum nondemolition detector is used.

Physical Review A•May 1, 1986•205 citations

Room temperature generation of amplitude squeezed light from 1550 nm distributed feedback semiconductor laser

Francine Jérémie, C. Chabran, Philippe B. Gallion

The control of the quantum state of light has recently been studied extensively, aiming at the achievement of ultra-low noise below the shot noise limit. Several experiments showed that amplitude squeezing could be achieved in constant-current-driven semiconductor lasers. However, the generation of amplitude-squeezed light from distributed feedback semiconductor lasers (DFB) has been up to now considerably less successful than that from Fabry-Perot devices. Simulations indicate that DFB structures with high coupling coefficient length product kL are unlikely to be good sources of squeezed light, because of the evanescence of the optical fields along the grating [1]. They also show, that for low kL values the lowest achievable intensity noise depends on the structure of the laser diode and can be higher than expected from the laser quantum efficiency alone.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jan 1, 1998•0 citations

Observation of amplitude squeezing in a constant-current-driven distributed feedback quantum dot laser with optical feedback

Shihao Ding, Shiyuan Zhao, Heming Huang +1 more

We illustrate the generation of single-mode amplitude squeezing in a distributed feedback quantum dot laser driven by a constant-current pump. Achieving broadband amplitude squeezing of 1.7 dB over a 10 GHz range at room temperature is realized by suppressing carrier noise and implementing optical feedback. The noise-corrected squeezing level reached 5.1 dB. Furthermore, the examination of the zero-delay second-order correlation function demonstrates the robust feedback stability of the amplitude-squeezed state in the quantum dot laser compared to a reference quantum well laser. This investigation lays the groundwork for future advancements in integrated optical quantum chips.

APL Quantum•Apr 15, 2024•9 citations
A constant-current--driven semiconductor laser produced a field with amplitude noise reduced to below the standard quantum limit by -1.7 dB (32%) over an entire frequency range from near dc to 1.1 GHz. The amplitude squeezing dependence on laser pump rate and optical loss was in good agreement with theoretical prediction. The new squeezed-state generation principle of high impedance suppression for pump-amplitude fluctuation was thus confirmed experimentally.
The pump amplitude fluctuation of a current-driven semiconductor laser can be suppressed to below the ordinary shot-noise level by ``high-impedance suppression.'' As a result of this pump-fluctuation suppression, the output of a current-driven semiconductor laser exhibits amplitude squeezing in the frequency region below the cavity bandwidth. The noise equivalent circuits and the quantum-mechanical Langevin equations are derived and discussed for clarifying the difference between an ordinary laser oscillator with shot-noise-limited pump fluctuation and a constant-current-driven semiconductor laser.
The intensity-noise properties of an injection-locked semiconductor laser were studied experimentally. The constant-current-driven semiconductor laser producing the amplitude-squeezed state whose intensity noise was reduced below the standard quantum limit (SQL) by 0.72 dB was injection-locked by an external master laser. The measured intensity-noise level of the injection-locked semiconductor laser was 0.91 dB below the SQL. This experimental result indicates that a phase-coherent amplitude-squeezed state or squeezed vacuum state together with a reference local oscillator wave can be generated directly by semiconductor laser systems.
A new scheme for generating an amplitude-squeezed state is proposed. The photon-flux fluctuation of a semiconductor-laser output wave is measured with a quantum nondemolition (QND) detector, and is negatively fed back to the laser pumping current. The operator Langevin equations are derived by combining the quantum-mechanical analyses on the laser internal-external field fluctuations, the quantum nondemolition detector based on an optical Kerr effect, and a negative-feedback circuit. The output wave features a reduced photon number noise below the standard quantum limit, 〈(\ensuremath{\Delta}n^)2{)}^{2})2〉^〉, and an enhanced phase noise above that, 〈(\ensuremath{\Delta}\ensuremath{\psi}^)2{)}^{2})2〉>(1/4)〈n^${〉}^{\mathrm{\ensuremath{-}}1}$, while the minimum uncertainty product is still preserved. The observed photoelectron statistics in a negative-feedback GaAs laser diode using a conventional p-i-n photodiode (not a QND detector) are shown to exhibit sub-Poissonian statistics with the variance 〈(\ensuremath{\Delta}n^)2{)}^{2})2〉apeq20.26〈n^〉. The measured photocurrent fluctuation spectral density is also indicated to be below the standard quantum limit by a factor of 0.2 (=-7 dB). The experimental results also confirm that such amplitude squeezing is only observed inside the feedback loop and cannot be extracted from the loop unless a quantum nondemolition detector is used.
The control of the quantum state of light has recently been studied extensively, aiming at the achievement of ultra-low noise below the shot noise limit. Several experiments showed that amplitude squeezing could be achieved in constant-current-driven semiconductor lasers. However, the generation of amplitude-squeezed light from distributed feedback semiconductor lasers (DFB) has been up to now considerably less successful than that from Fabry-Perot devices. Simulations indicate that DFB structures with high coupling coefficient length product kL are unlikely to be good sources of squeezed light, because of the evanescence of the optical fields along the grating [1]. They also show, that for low kL values the lowest achievable intensity noise depends on the structure of the laser diode and can be higher than expected from the laser quantum efficiency alone.
We illustrate the generation of single-mode amplitude squeezing in a distributed feedback quantum dot laser driven by a constant-current pump. Achieving broadband amplitude squeezing of 1.7 dB over a 10 GHz range at room temperature is realized by suppressing carrier noise and implementing optical feedback. The noise-corrected squeezing level reached 5.1 dB. Furthermore, the examination of the zero-delay second-order correlation function demonstrates the robust feedback stability of the amplitude-squeezed state in the quantum dot laser compared to a reference quantum well laser. This investigation lays the groundwork for future advancements in integrated optical quantum chips.