Enhancement of Kerr rotation with amorphous Si film

Nakamura, Koshi; Asaka, T.; Asari, S.; Ota, Yasutomo; Itoh, A.

doi:10.1109/tmag.1985.1063911

Cited by 17 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This effect has been known for almost half a century, and enhancements of less than an order of magnitude have been reported that involve purely reflection from a magnetic surface 5,6 . For a single dielectric layer, it is straightforward to calculate the polarization rotation from the cavity, and with an appropriate choice of lossless dielectric constant, arbitrarily large enhancements are in principle possible 7 .…”

Section: Theoretical Treatmentmentioning

confidence: 99%

Cavity-enhanced near-field optical magnetometry

2004

View full text Add to dashboard Cite

We present the first near-field scanning optical magneto-optic Kerr effect (MOKE) of sub-micron magnetic structures, where a Kerr rotation of 0.11º from a 0.25µm nickel magnet was observed. This is enabled by a cavity based technique to enhance the Kerr rotation of light reflected from a magnetized surface. Spatially resolved magneto-optic measurements are performed involving both conventional microscopy and near-field scanning optical microscopy (NSOM). Cavity enhancement is achieved with either a single dielectric coating or a dielectric-metal bilayer coating applied to the ferromagnetic structure of interest. We present a scattering matrix approach to calculating the enhancement resulting from a multilayer dielectric coating and show good agreement with experiment. This demonstrates a non-invasive optical technique for magnetometry with ultrahigh spatial resolution.

show abstract

Section: Theoretical Treatmentmentioning

confidence: 99%

Cavity-enhanced near-field optical magnetometry

2004

View full text Add to dashboard Cite

show abstract

“…It has been reported that θ K of a magnetic layer can be increased by depositing dielectric lms on the magnetic surface. 6,7) This is caused by the cavity effect, where the dielectric layer acts as a Fabry-Pérot etalon that allows multiple re ections off the magnetic layer. MO enhancement up to a factor of 4 has been obtained using a single dielectric lm, 7) and has reached a value of approximately 16 (θ K ~ 1.6 ) by using a SiO 2 dielectric lm with a thin gold-coating layer.…”

Section: Effect Of a Zno Intermediate Layer On Copt/agmentioning

confidence: 99%

“…6,7) This is caused by the cavity effect, where the dielectric layer acts as a Fabry-Pérot etalon that allows multiple re ections off the magnetic layer. MO enhancement up to a factor of 4 has been obtained using a single dielectric lm, 7) and has reached a value of approximately 16 (θ K ~ 1.6 ) by using a SiO 2 dielectric lm with a thin gold-coating layer. 9) In our system, the CoPt layer acts as a dual functional layer, ful lling the roles of both magnetic and coating lms.…”

Section: Effect Of a Zno Intermediate Layer On Copt/agmentioning

confidence: 99%

“…Similarly, MO cavities consisting of stacked layer structure enhance the MO effect by multiple re ections of light inside the structure. [6][7][8][9][10] The cavities are typically formed by a re ective layer as a mirror, magnetic layer, a spacer and a capping layer. In recent years, it has been reported that the MO cavities indicate a relatively large Kerr rotation angle reaching to several degrees.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Magneto-Optical Enhancement and Chemical Sensing Applications of Perpendicular Magnetic CoPt/Ag Stacked Structures with a ZnO Intermediate Layer

2016

View full text Add to dashboard Cite

The magneto-optical (MO) properties of perpendicular magnetic Co 80 Pt 20 /Ag stacked lms with ZnO intermediate layers of different thickness were investigated by polar Kerr measurements. The insertion of a thin ZnO layer at the CoPt/Ag interface improved the perpendicular magnetic properties and MO enhancement at the plasma edge of Ag. The CoPt/Ag stacked lms with a 2-nm-thick ZnO layer exhibited an ideal square out-of-plane hysteresis loop with a relatively large Kerr angle of approximately 1.4 in the ultraviolet region. The peak position of the MO plasma enhancement shifted to longer wavelength as the thickness of the ZnO layer increased, and a new peak appeared consistent with the band-gap energy of ZnO. Moreover, the CoPt/ZnO/Ag stacked layer acted as a Fabry-Pérot etalon when the thickness of the ZnO layer was the sub-wavelength of incident light. As a result, a MO cavity was realized in the stacked lms, and an ideal square MO loop with a large Kerr rotation angle of approximately 20 was obtained in the visible region. The MO enhancement factor reached approximately 200. We demonstrated that the stacked lms were sensitive to changes in the optical conditions at the lm surface. The developed MO cavity can act as a highly accurate chemical and biological sensing system under simple measurement conditions.

show abstract

“…Therefore differential imaging and exposure time of the order of 1 s have to be used [22]. It is well known that this rotation angle and thus the magnetic contrast can be enhanced by using multiple reflections in an additional anti-reflecting dielectric layer deposited onto the surface of metallic magnetic samples [19,23,24,25]. However this has not yet been evidenced with magnetic semiconductorsin which the typical penetration depth of light can be of several hundreds of nm.…”

Section: Introductionmentioning

confidence: 99%

Optimizing magneto-optical effects in the ferromagnetic semiconductor GaMnAs

Riahi

Thevenard

Maaref

et al. 2015

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

A trilayer of the ferromagnetic semiconductor GaMnAs, a SiO 2 buffer layer and a piezoelectric ZnO layer is investigated in view of its use in device implementation to study surface acoustic wave assisted magnetization switching. The magneto-optical properties: Kerr rotation and ellipticity and magnetic contrast in Kerr microscopy images are investigated as a function of temperature. While the ZnO layer prevents any good quality imaging of magnetic domains, we show that with the SiO 2 layer only the polar Kerr rotation and the magnetic contrast are increased by a factor 2. This result is in good quantitative agreement with calculations using an optical interference model and could be further improved. The detrimental effects of the dielectric layers overgrowth on the Curie temperature and coercive field of the GaMnAs layer can be kept to a reasonable level.

show abstract

Enhancement of Kerr rotation with amorphous Si film

Cited by 17 publications

References 0 publications

Cavity-enhanced near-field optical magnetometry

Cavity-enhanced near-field optical magnetometry

Magneto-Optical Enhancement and Chemical Sensing Applications of Perpendicular Magnetic CoPt/Ag Stacked Structures with a ZnO Intermediate Layer

Optimizing magneto-optical effects in the ferromagnetic semiconductor GaMnAs

Contact Info

Product

Resources

About