White-light versus discrete wavelength measurements of Faraday dispersion and the Verdet constant

Maxwell, James L; Hughes, Ifan G.; Adams, Charles S.

doi:10.1088/1361-6404/ac31d3

Cited by 3 publications

(3 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Faraday effect is expressed as θ B (λ) = V(λ)Bl. The Verdet constant is an important parameter for Faraday effect, which depends on the properties of the material, temperature and λ [18]. The influence of air on the Faraday rotation of the system is also worth discussing, and it has been investigated by Al-Basheer [19] and Wu et al [20].…”

Section: Introductionmentioning

confidence: 99%

Measurement of rubidium vapor number density based on Faraday modulator

Shang¹,

Zhou²,

Quan³

et al. 2022

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The actual vapor density characterizing the alkali metal spin-exchange rate remains a compelling issue for spin-exchange optical pumping. Based on the deduced relationship between the Faraday rotation angle and the rubidium vapor number density using the electron dynamics theory, we report a measurement of the number density for rubidium vapor sealed inside a cell based on a Faraday modulator. The measurement relies on the optical rotation angle due to Rubidium vapor under a bias magnetic field (~0.08 T) produced by a samarium-cobalt magnet. A Faraday modulator with a lock-in amplifier is used to accurately measure the tiny optical rotation angle in a temperature range of 387~468 K. In addition, a synchronization verification is performed by the photoelastic modulator. The recurring data showed that the two methods are consistent with each other. Compared with the photoelastic modulator (PEM) method, the Faraday modulator detection system does not need to adjust the optical axis difference of 45° in the PEM detection system, thereby reducing the complexity of the experiment and the error caused by the alignment of the optical axis, which showed that the Faraday modulator detection method more advantageous in measuring the alkali metal density.

show abstract

Section: Introductionmentioning

confidence: 99%

Measurement of rubidium vapor number density based on Faraday modulator

Shang¹,

Zhou²,

Quan³

et al. 2022

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…The power of the incident laser light was adjusted carefully to avoid saturating the photodiode. Note that both white-light and discrete-wavelength sources are used in this study, but that for quantitative measurements of ORD (and similar phenomena, such as the magneto-optical Faraday effect), the use of discrete wavelengths is less prone to systematic errors [ 38 ].…”

Section: Methodsmentioning

confidence: 99%

Measurements of large optical rotary dispersion in the adipose eyelid of Atlantic mackerel ( Scomber scombrus )

Jenkinson

Alexander

Camp

2023

J. R. Soc. Interface.

View full text Add to dashboard Cite

Collagen is the most prevalent of Nature’s structural proteins, and is found in the extracellular matrices of animals. The structures of collagen molecules and aggregates are chiral, which leads to the rotation of transmitted, plane-polarized light. Here, it is shown that the concentrations of chiral molecules and aggregates in the optically transparent, adipose eyelid of Atlantic mackerel ( Scomber scombrus ) can be so high, that plane-polarized light in the visible spectrum is rotated by tens to hundreds of degrees, depending on wavelength (the optical rotatory dispersion (ORD)). This gives rise to intensely coloured images of eyelid samples when illuminated with white light and viewed between crossed polarizers. The ORD in the visible spectrum is measured with monochromatic light sources, and using this dispersion, the variation of optical thickness within a sample (proportional to collagen concentration and path length) is determined. The agreement between observed and simulated white-light images is almost perfect. While collagen provides vital mechanical rigidity to animal tissue, it might also possess optical properties that are useful for vision and camouflage.

show abstract

“…The HT technique is applied to both of these systems, leading to an indirect measurement of the two refractive indices n 1,2 for each geometry via simple absorption spectroscopy. Notably, while previous research has focused on measuring total magnetooptical rotation [67,[76][77][78][79][80][81][82][83][84][85][86][87][88], to our knowledge, the two individual refractive indices have never been separately measured in studies of atomic thermal vapours 2 . Measuring the difference ∆n = n 2 − n 1 ultimately provides an indirect measurement of atomic magneto-optical rotation via the HT.…”

Section: Introductionmentioning

confidence: 99%

Indirect measurement of atomic magneto-optical rotation via Hilbert transform

Briscoe,

Pizzey,

Wrathmall

et al. 2024

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

The Kramers-Kronig relations are a pivotal foundation of linear optics and atomic physics, embedding a physical connection between the real and imaginary components of any causal response function. A mathematically equivalent, but simpler, approach instead utilises the Hilbert transform. In a previous study, the Hilbert transform was applied to absorption spectra in order to infer the sole refractive index of an atomic medium in the absence of an external magnetic field. The presence of a magnetic field causes the medium to become birefringent and dichroic, and therefore it is instead characterised by two refractive indices. In this study, we apply the same Hilbert transform technique to independently measure both refractive indices of a birefringent atomic medium, leading to an indirect measurement of atomic magneto-optical rotation. Key to this measurement is the insight that inputting specific light polarisations into an atomic medium induces absorption associated with only one of the refractive indices. We show this is true in two configurations, commonly referred to in literature as the Faraday and Voigt geometries, which differ by the magnetic field orientation with respect to the light wavevector. For both cases, we measure the two refractive indices independently for a Rb thermal vapour in a 0.6 T magnetic field, finding excellent agreement with theory. This study further emphasises the application of the Hilbert transform to the field of quantum and atomic optics in the linear regime.

show abstract

White-light versus discrete wavelength measurements of Faraday dispersion and the Verdet constant

Cited by 3 publications

References 41 publications

Measurement of rubidium vapor number density based on Faraday modulator

Measurement of rubidium vapor number density based on Faraday modulator

Measurements of large optical rotary dispersion in the adipose eyelid of Atlantic mackerel ( Scomber scombrus )

Indirect measurement of atomic magneto-optical rotation via Hilbert transform

Contact Info

Product

Resources

About