A spectroscopic unit includes a housing, a light incident portion provided in the housing, a Fabry-Perot interference filter arranged in the housing and having a first mirror and a second mirror, a distance between the first mirror and the second mirror being variable. The light incident portion includes an aperture portion in which an aperture is formed and a band pass filter arranged between the aperture and the Fabry-Perot interference filter. The aperture portion is configured so that a value obtained by dividing a length of the aperture in a facing direction of the first mirror and the second mirror by a width of the aperture in a direction perpendicular to the facing direction is equal to or more than 0.5 and the entirety of light passing through the aperture is incident on the band pass filter.

A method is disclosed for increasing an intensity of a signal detected in a spectroscopy device using a vapor cell and a spectroscopy device using the same. An operation method of the spectroscopy device may include: causing a first light for exciting an atom trapped in a vapor cell in a first hyperfine ground state to a first excited state to be incident on the vapor cell; causing a second light for exciting an atom trapped in the vapor cell in a second hyperfine ground state to a second excited state to be incident on the vapor cell; causing a third light for exciting the atom in the second excited state to a third excited state to be incident on the vapor cell; and detecting fluorescence which is emitted while the atom in the third excited state returns to the ground state.

A method is disclosed for increasing an intensity of a signal detected in a spectroscopy device using a vapor cell and a spectroscopy device using the same. An operation method of the spectroscopy device may include: causing a first light for exciting an atom trapped in a vapor cell in a first hyperfine ground state to a first excited state to be incident on the vapor cell; causing a second light for exciting an atom trapped in the vapor cell in a second hyperfine ground state to a second excited state to be incident on the vapor cell; causing a third light for exciting the atom in the second excited state to a third excited state to be incident on the vapor cell; and detecting fluorescence which is emitted while the atom in the third excited state returns to the ground state.

A spectroscopic unit includes a housing, a light incident portion provided in the housing, a Fabry-Perot interference filter arranged in the housing and having a first mirror and a second mirror, a distance between the first mirror and the second mirror being variable. The light incident portion includes an aperture portion in which an aperture is formed and a band pass filter arranged between the aperture and the Fabry-Perot interference filter. The aperture portion is configured so that a value obtained by dividing a length of the aperture in a facing direction of the first mirror and the second mirror by a width of the aperture in a direction perpendicular to the facing direction is equal to or more than 0.5 and the entirety of light passing through the aperture is incident on the band pass filter.

A spectroscopic unit includes a housing, a light incident portion provided in the housing, a Fabry-Perot interference filter arranged in the housing and having a first mirror and a second mirror, a distance between the first mirror and the second mirror being variable. The light incident portion includes an aperture portion in which an aperture is formed and a band pass filter arranged between the aperture and the Fabry-Perot interference filter. The aperture portion is configured so that a value obtained by dividing a length of the aperture in a facing direction of the first mirror and the second mirror by a width of the aperture in a direction perpendicular to the facing direction is equal to or more than 0.5 and the entirety of light passing through the aperture is incident on the band pass filter.

Embodiments herein describe various arrangements of an optical bench used to perform spectroscopy. For example, a spectroscopy system may include a pump optical signal and a probe optical signal that are transmitted through a vapor cell on the optical bench. The optical bench can further include one or more optical components (e.g., beam splitter and a thin film polarizer) for redirecting a portion of the probe and pump optical signals to photodiodes. In one embodiment, the measurements obtained from the photodiodes can be used to perform multiple tasks. For example, the measurements can be used to adjust the power of the optical signals in the optical bench (e.g., make DC power adjustments), perform amplitude modulation correction, and lock a laser frequency to a peak of an absorption spectrum of the vapor in the vapor cell.

A spectroscopic unit includes a housing, a light incident portion provided in the housing, a Fabry-Perot interference filter arranged in the housing and having a first mirror and a second mirror, a distance between the first mirror and the second mirror being variable. The light incident portion includes an aperture portion in which an aperture is formed and a band pass filter arranged between the aperture and the Fabry-Perot interference filter. The aperture portion is configured so that a value obtained by dividing a length of the aperture in a facing direction of the first mirror and the second mirror by a width of the aperture in a direction perpendicular to the facing direction is equal to or more than 0.5 and the entirety of light passing through the aperture is incident on the band pass filter.

Embodiments herein describe various arrangements of an optical bench used to perform spectroscopy. For example, a spectroscopy system may include a pump optical signal and a probe optical signal that are transmitted through a vapor cell on the optical bench. The optical bench can further include one or more optical components (e.g., beam splitter and a thin film polarizer) for redirecting a portion of the probe and pump optical signals to photodiodes. In one embodiment, the measurements obtained from the photodiodes can be used to perform multiple tasks. For example, the measurements can be used to adjust the power of the optical signals in the optical bench (e.g., make DC power adjustments), perform amplitude modulation correction, and lock a laser frequency to a peak of an absorption spectrum of the vapor in the vapor cell.

A surface plasmon resonance spectrometer includes a substrate, a first dielectric spacer, a detector, a second dielectric spacer, and a plurality of metal scattering structures. The substrate includes a region having a permittivity gradient. The first dielectric spacer is positioned on the substrate at a location corresponding to the region having the permittivity gradient. The detector is positioned over the region having the permittivity gradient with the first dielectric spacer therebetween. The second dielectric spacer is positioned on the detector opposite the first dielectric spacer. The plurality of metal scattering structures are positioned on the second dielectric spacer opposite the detector.