The pulsed squeezed state of light is expected to enhance the sensitivity of optical measurements using optical pulses. To achieve a high squeezing level, it is crucial to explore its limiting factors. In this study, we analyze the pulsed squeezed vacuum detected with picosecond pulses to explore two critical factors that limit the achievable squeezing level. First, we investigate the effect of the frequency chirp of local oscillator (LO) pulses and show that there exists an upper bound of the chirp parameter for a given squeezing level. Next, we analyze the effect of temporal matching between the LO pulse and the squeezed vacuum and point out the importance of temporal broadening in nonlinear optical crystals for squeezing.The pulsed squeezed state of light is expected to enhance the sensitivity of optical measurements using optical pulses. To achieve a high squeezing level, it is crucial to explore its limiting factors. In this study, we analyze the pulsed squeezed vacuum detected with picosecond pulses to explore two critical factors that limit the achievable squeezing level. First, we investigate the effect of the frequency chirp of local oscillator (LO) pulses and show that there exists an upper bound of the chirp parameter for a given squeezing level. Next, we analyze the effect of temporal matching between the LO pulse and the squeezed vacuum and point out the importance of temporal broadening in nonlinear optical crystals for squeezing.

Journal of the Optical Society of America BMar 31, 202015 citations

Phase locking scheme for squeezed vacuum generated by single-pass optical parametric amplifier

Yoshitaka Taguchi, Yasuyuki Ozeki

Single-pass optical parametric amplification (OPA) is attractive in the generation of broadband squeezed vacuum. To achieve a higher squeezing level, precise control of the local oscillator (LO) phase is needed. However, the conventional control scheme was designed for squeezing by optical parametric oscillation (OPO). In this study, we propose a new scheme, which is applicable to single-pass OPA. In this scheme, we measure the modulation in the residual pump light after the OPA crystal to realize precise phase-locking of the LO. We anticipate that the proposed scheme will be indispensable for practical applications of squeezing with single-pass OPA.Single-pass optical parametric amplification (OPA) is attractive in the generation of broadband squeezed vacuum. To achieve a higher squeezing level, precise control of the local oscillator (LO) phase is needed. However, the conventional control scheme was designed for squeezing by optical parametric oscillation (OPO). In this study, we propose a new scheme, which is applicable to single-pass OPA. In this scheme, we measure the modulation in the residual pump light after the OPA crystal to realize precise phase-locking of the LO. We anticipate that the proposed scheme will be indispensable for practical applications of squeezing with single-pass OPA.

Optical and Quantum Sensing and Precision Metrology IIMar 3, 20220 citations

Coherent control of broadband vacuum squeezing

S. Chelkowski, H. Vahlbruch, K. Danzmann +1 more

We present the observation of optical fields carrying squeezed vacuum states at sideband frequencies from $10\phantom{\rule{0.3em}{0ex}}\mathrm{Hz}$ to above $35\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$ . The field was generated with type-I optical parametric oscillation below threshold at $1064\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ . A coherent, unbalanced classical modulation field at $40\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$ enabled the generation of error signals for stable phase control of the squeezed vacuum field with respect to a strong local oscillator. Broadband squeezing of approximately $\ensuremath{-}4\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$ was measured with balanced homodyne detection. The spectrum of the squeezed field allows a quantum noise reduction of ground-based gravitational wave detectors over their full detection band, regardless of whether homodyne readout or radio-frequency heterodyne readout is used.We present the observation of optical fields carrying squeezed vacuum states at sideband frequencies from $10\phantom{\rule{0.3em}{0ex}}\mathrm{Hz}$ to above $35\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$. The field was generated with type-I optical parametric oscillation below threshold at $1064\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. A coherent, unbalanced classical modulation field at $40\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$ enabled the generation of error signals for stable phase control of the squeezed vacuum field with respect to a strong local oscillator. Broadband squeezing of approximately $\ensuremath{-}4\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$ was measured with balanced homodyne detection. The spectrum of the squeezed field allows a quantum noise reduction of ground-based gravitational wave detectors over their full detection band, regardless of whether homodyne readout or radio-frequency heterodyne readout is used.

arXiv:0704.3796Physical Review AApr 23, 200771 citations

Determination of weakly squeezed vacuum states through photon statistics measurement

Guan-Hua Zuo, Yuchi Zhang, Jing Li +3 more

Physics Letters AApr 12, 202211 citations

We present the observation of optical fields carrying squeezed vacuum states at sideband frequencies from

10\phantom{\rule{0.3em}{0ex}}\mathrm{Hz}

to above

35\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}

. The field was generated with type-I optical parametric oscillation below threshold at

1064\phantom{\rule{0.3em}{0ex}}\mathrm{nm}

. A coherent, unbalanced classical modulation field at

40\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}

enabled the generation of error signals for stable phase control of the squeezed vacuum field with respect to a strong local oscillator. Broadband squeezing of approximately $\ensuremath{-}4\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$ was measured with balanced homodyne detection. The spectrum of the squeezed field allows a quantum noise reduction of ground-based gravitational wave detectors over their full detection band, regardless of whether homodyne readout or radio-frequency heterodyne readout is used.