Sensitive Faraday rotation measurement with auto-balanced photodetection

Chang, Chia-Yu; Wang, Likarn; Shy, Jow−Tsong; Lin, Chu-En; Chou, Chien

doi:10.1063/1.3602927

Cited by 23 publications

(20 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sensitivity at the ratio of 1 is estimated to be more 50% higher than that of 2. For example, we set the ratio at 1.77 in our previous air Faraday rotation measurement, and a sensitivity of 2.99 × 10 −8 rad Hz −1∕2 was achieved [8]. The sensitivity could reach 2.06 × 10 −8 rad Hz −1∕2 if we set the ratio to 1.…”

Section: Resultsmentioning

confidence: 98%

“…1. The setup is the same as our previous setup for air Faraday measurement [8], except the light source is replaced by a two-mode stabilized 632.8 nm He-Ne laser. After the optical isolator, the beam is linearly polarized, and its power is 0.42 mW.…”

Section: Methodsmentioning

confidence: 99%

“…The Verdet constants of gases are smaller than those of liquids and solids by three orders of magnitude. We have been able to measure the tiny air Faraday effect with autobalanced photodetection [8]. In this paper, we report and discuss the measurement of air Faraday rotation at different azimuth angles of polarization which correspond to different power split ratios of reference beam to signal beam.…”

Section: Introductionmentioning

confidence: 99%

“…Later, the ratio was suggested as being close to 2 to get the best noise cancellation [7]. In our previous air Faraday rotation measurement we set the ratio at 1.77 [8], and in Faraday rotation spectroscopy for oxygen detection by Brumfield and Wysocki the ratio was set from 1.6 to 2 [9].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Optimal power split ratio for autobalanced photodetection

Chang

Shy

2014

Appl. Opt.

Self Cite

View full text Add to dashboard Cite

The noise suppression of the autobalanced photoreceiver devised by Hobbs [Proc. SPIE1376, 216 (1990)] had been determined to depend on the photocurrent ratio of reference beam to signal beam under the condition of constant signal beam photocurrent, and the best noise cancellation was suggested at a ratio close to 2. But in most applications, the available optical power has a limit. Therefore, to optimize the sensitivity of measurements, we should consider how to allocate the beam power in the case of fixed total optical power. In this paper, we measure the air Faraday rotation at different azimuth angles of beam polarization, which correspond to different photocurrent ratios. The signal-to-noise ratio at each photocurrent ratio is determined, and the best sensitivity appears at the photocurrent ratio of 1. This best sensitivity achieved is 3.02×10(-8) rad Hz(-1/2), which is about 1.3 times the shot noise limit. Our results are useful for sensitive optical measurements with the autobalanced photoreceiver.

show abstract

Section: Resultsmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optimal power split ratio for autobalanced photodetection

Chang

Shy

2014

Appl. Opt.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The polarization-bridge configuration is employed to attain the maximum sensitivity of polarimetric measurement, with the linear polarization direction of the probe beam being horizontal. [16,17] Parallel and perpendicular polarization-components of a linearly polarized probe beam are separated by a Wollaston prism, and transient ORP at a given wavelength is extracted from the intensities of two orthogonal polarization-components. See the Supporting Information for schematic diagram of the transient ORP setup and detailed description.…”

Section: Pump-probe Transient Measurement Of Optical Rotatory Dispersionmentioning

confidence: 99%

Time‐Resolved Pump–Probe Measurement of Optical Rotatory Dispersion in Chiral Metamaterial

Woo

Kang

Gwon

et al. 2017

Advanced Optical Materials

View full text Add to dashboard Cite

A plasmonic chiral metamaterial is fabricated from a thin Au film and exhibits static optical rotatory power (ORP) in the visible spectral range. Transient ORP is measured to clarify the temporal development of ORP using a circularly polarized light (CPL) pump beam. Three distinct transient behaviors of ORP are identified, resulting from different energy relaxation processes of hot electrons that occur during a period of a few picoseconds after pumping. Nonthermal hot electrons experience Lorentz force from an inverse Faraday effect and electron–boundary scattering, yielding a pump beam CPL helicity‐dependent transient ORP. Once hot electrons are in thermal equilibrium with the lattice, electron energy is distributed among the occupied states, as described by Fermi–Dirac statistics. Moreover, the transient ORP is independent of pump beam CPL helicity, well explained by the selection rule of electron excitation and two‐temperature model of the electron cooling process. Theoretical analysis of the transient ORP in terms of the energy relaxation of thermal hot electrons is carried out by introducing a temperature‐dependent dielectric function and finite‐difference time‐domain simulation. It is found that the magnitude of ORP at an elevated temperature is reduced to less than that at room temperature, agreeing well with the experimental observation.

show abstract

Highly Sensitive Polarization Rotation Measurement through a High‐Order Vector Beam Generated by a Metasurface

Yue

Aglieri

Piccoli

et al. 2020

Adv Materials Technologies

View full text Add to dashboard Cite

The precise determination of the polarization state of light is fundamental for a vast variety of applications in remote sensing, astronomy, optics and terahertz technology, to name just a few. Typically, polarization characterization is performed by using a combination of multiple optical devices such as beam splitters, polarizers, and waveplates. Moreover, to achieve highprecision, balanced photodetectors and lock-in amplifiers are employed, thus contributing to increasing system complexity. Here, a technique for polarization rotation measurements with a dynamic range of 180° and a sensitivity of about 10−2 degrees is realized using a properly designed metasurface. Such device generates a vector beam with an azimuthally-dependent polarization distribution, as a result of the superposition of two vortex beams carrying opposite orbital angular momenta (ℓ = ±30). After propagation through a linear polarizer, the spatial intensity profile of such a beam turns into 60 lobes. By tracking the displacement of only two of these lobes on a camera, the rotation of the input polarization state can be retrieved with high resolution. The proposed approach offers a new route toward the development of compact high-precision polarimeters and can also be exploited in quantum information processing, optical communications, as well as nonlinear and chiral optics.

show abstract

Sensitive Faraday rotation measurement with auto-balanced photodetection

Cited by 23 publications

References 10 publications

Optimal power split ratio for autobalanced photodetection

Optimal power split ratio for autobalanced photodetection

Time‐Resolved Pump–Probe Measurement of Optical Rotatory Dispersion in Chiral Metamaterial

Highly Sensitive Polarization Rotation Measurement through a High‐Order Vector Beam Generated by a Metasurface

Contact Info

Product

Resources

About