Measuring near-field optical distributions emitted from chip surface of photonic crystal patterned light emitting diodes

Park, Kyoung‐Duck; Ji, Wonsoo; Park, Dae-Seo; Kim, Dae-Chan; Beom‐Hoan, O; Park, Se-Geun; Lee, El-Hang; Lee, Seung Gol

doi:10.1117/12.780816

Cited by 2 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The near-field scanning optical microscope (NSOM) is a high resolution imaging tool used in measuring both the surface profile and the near-field optical signal of a sample, and thus has been widely used in such research fields as the measurement of micro/nanophotonic devices, [1][2][3][4][5][6][7] plasmonic devices, 8,9 semiconductor devices, [10][11][12] and biomaterials, [13][14][15][16] etc. In addition, it plays an important role in the field of nanolithography.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity maximized near-field scanning optical microscope with dithering sample stage

Park

Lee

Heo

et al. 2012

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

We developed a new scheme for a higher sensitivity near-field scanning optical microscope (NSOM) by using a dithering sample stage rather than a dithering probe for the constant gap control between probe and sample. In a conventional NSOM, which use tip dithering feedback mechanism, the Q factor drastically decreases from 7783 to 1000 (13%) or even to 100 (1%) because harmonic oscillating characteristic is deteriorated owing to the large change of stiffness and mass of one prong of tuning fork when a probe is attached to it. In our proposed scheme, on the other hand, we use sample dithering feedback mechanism, where the probe is not attached to the tuning fork and the sample is loaded directly onto the surface of dithering tuning fork. Thus, the Q factor does not decrease significantly, from only 7783 to 7480 (96%), because the loaded sample hardly changes the stiffness and mass of tuning fork. Accordingly, gap control between the immobile fiber probe and the dithering sample is performed precisely by detecting the shear force with high sensitivity. Consequently, the extremely high Q factor enables clear observation of graphene sheets with sub-nanometer vertical resolution, which is not possible with a conventional NSOM setup.

show abstract

Section: Introductionmentioning

confidence: 99%

Sensitivity maximized near-field scanning optical microscope with dithering sample stage

Park

Lee

Heo

et al. 2012

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

show abstract

In-situ mapping of electroluminescent enhancement of light-emitting diodes grown on patterned sapphire substrates

Lee

et al. 2017

Journal of Applied Physics

View full text Add to dashboard Cite

The mechanism for enhancing extraction efficiency of light emitting diodes (LEDs) grown on patterned sapphire substrates (PSSs) was observed by the in-situ lateral electroluminescence (EL) mapping using optical microscopy equipped with a laser energy profiler. The observed spatial intensity distribution of epilayers, varying from epilayer to epilayer on the lateral surface of the PSS LED chip, revealed that the perimeter scattering on the convex facets of PSSs converges the propagation of emitted light with random directionality into a spot near the top surface of the buffer layer. Moreover, this in-situ sidewall mapping implied that the enhancement of light extraction of the PSS LED is due to reducing the total internal reflection effect, resulting from the spot located closer to the LED/air interface. Simulated results and EL images of convex patterns on the PSS surface were consistent with sidewall surface-based observations.

show abstract

Measuring near-field optical distributions emitted from chip surface of photonic crystal patterned light emitting diodes

Cited by 2 publications

References 0 publications

Sensitivity maximized near-field scanning optical microscope with dithering sample stage

Sensitivity maximized near-field scanning optical microscope with dithering sample stage

In-situ mapping of electroluminescent enhancement of light-emitting diodes grown on patterned sapphire substrates

Contact Info

Product

Resources

About