---
_id: '67133'
abstract:
- lang: eng
  text: <jats:p>We investigated the spectral properties of squeezed light generated
    via parametric down-conversion in the high-gain regime, considering both unapodized
    and apodized dispersion-engineered waveguides. The gain-dependent evolution of
    these states is examined starting from the low-gain regime, which includes both
    highly correlated and nearly uncorrelated cases. For the unapodized configuration,
    our simulated results show a monotonic increase in spectral purity with gain,
    whereas for some of the apodized configuration, they exhibit a nonmonotonic dependence,
    initially decreasing and then recovering at higher gain. By combining Schmidt-mode
    analysis with a group-velocity-based interpretation, we explain why different
    dispersion conditions exhibit distinct gain-dependent behavior, specifically that
    rapid purification occurs when the pump group velocity lies between those of the
    signal and idler. Our study shows that the evolution of spectral purity is governed
    primarily by the underlying dispersion of the waveguide. These results demonstrate
    that dispersion engineering and parametric gain can be jointly exploited to tailor
    the spectral-mode structure of squeezed-light sources, enabling their optimization
    for a broad range of quantum applications.</jats:p>
article_number: '023706'
author:
- first_name: Jatin
  full_name: Kumar, Jatin
  last_name: Kumar
- first_name: Aleksa
  full_name: Krstić, Aleksa
  last_name: Krstić
- first_name: Sina
  full_name: Saravi, Sina
  last_name: Saravi
- first_name: Frank
  full_name: Setzpfandt, Frank
  last_name: Setzpfandt
citation:
  ama: Kumar J, Krstić A, Saravi S, Setzpfandt F. Toward spectral engineering of squeezed
    light in high-gain parametric down-conversion. <i>Physical Review A</i>. 2026;114(2).
    doi:<a href="https://doi.org/10.1103/2hth-yy33">10.1103/2hth-yy33</a>
  apa: Kumar, J., Krstić, A., Saravi, S., &#38; Setzpfandt, F. (2026). Toward spectral
    engineering of squeezed light in high-gain parametric down-conversion. <i>Physical
    Review A</i>, <i>114</i>(2), Article 023706. <a href="https://doi.org/10.1103/2hth-yy33">https://doi.org/10.1103/2hth-yy33</a>
  bibtex: '@article{Kumar_Krstić_Saravi_Setzpfandt_2026, title={Toward spectral engineering
    of squeezed light in high-gain parametric down-conversion}, volume={114}, DOI={<a
    href="https://doi.org/10.1103/2hth-yy33">10.1103/2hth-yy33</a>}, number={2023706},
    journal={Physical Review A}, publisher={American Physical Society (APS)}, author={Kumar,
    Jatin and Krstić, Aleksa and Saravi, Sina and Setzpfandt, Frank}, year={2026}
    }'
  chicago: Kumar, Jatin, Aleksa Krstić, Sina Saravi, and Frank Setzpfandt. “Toward
    Spectral Engineering of Squeezed Light in High-Gain Parametric down-Conversion.”
    <i>Physical Review A</i> 114, no. 2 (2026). <a href="https://doi.org/10.1103/2hth-yy33">https://doi.org/10.1103/2hth-yy33</a>.
  ieee: 'J. Kumar, A. Krstić, S. Saravi, and F. Setzpfandt, “Toward spectral engineering
    of squeezed light in high-gain parametric down-conversion,” <i>Physical Review
    A</i>, vol. 114, no. 2, Art. no. 023706, 2026, doi: <a href="https://doi.org/10.1103/2hth-yy33">10.1103/2hth-yy33</a>.'
  mla: Kumar, Jatin, et al. “Toward Spectral Engineering of Squeezed Light in High-Gain
    Parametric down-Conversion.” <i>Physical Review A</i>, vol. 114, no. 2, 023706,
    American Physical Society (APS), 2026, doi:<a href="https://doi.org/10.1103/2hth-yy33">10.1103/2hth-yy33</a>.
  short: J. Kumar, A. Krstić, S. Saravi, F. Setzpfandt, Physical Review A 114 (2026).
date_created: 2026-09-12T10:08:24Z
date_updated: 2026-09-12T10:10:11Z
department:
- _id: '975'
doi: 10.1103/2hth-yy33
intvolume: '       114'
issue: '2'
language:
- iso: eng
publication: Physical Review A
publication_identifier:
  issn:
  - 2469-9926
  - 2469-9934
publication_status: published
publisher: American Physical Society (APS)
status: public
title: Toward spectral engineering of squeezed light in high-gain parametric down-conversion
type: journal_article
user_id: '115260'
volume: 114
year: '2026'
...