Beam divergence and waist measurements of laser diodes by near-field scanning optical microscopy

Herzog, W.D.; Ünlü, M. Selim; Goldberg, B. B.; Rhodes, G.H. Vander; Harder, C.

doi:10.1063/1.118258

Cited by 49 publications

(17 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1][2][3][4][5] By scanning an optical fiber probe above the facet of a laser diode ͑LD͒ in near-field zone, collection mode SNOM can collect the near-field optical intensity output from LD, while excitation mode SNOM generates the contrast of near-field optical beam induced current ͑NOBIC͒ to form an image. Subwavelength spatial information on LD structure, performance, and output properties can be obtained.…”

mentioning

confidence: 99%

Optical characterization of visible multiquantum-well semiconductor lasers by collection/excitation modes of scanning near-field optical microscopy

Tsai

Chang

et al. 1999

Applied Physics Letters

View full text Add to dashboard Cite

Both collection and excitation modes of scanning near-field optical microscopy were used to study a strained AlGaInP/Ga 0.4 In 0.6 P low power visible multiquantum-well laser diode. Collection and excitation modes provide the near-field optical propagating intensity distribution and local photoconductivity information, respectively, at the facet of laser diode. Results show highly localized spatial correlation of the laser diode structure and its optical performance at the facet. Defect level in the energy range of 60-380 meV below the conduction band in the highly n-doped ͑Al 0.7 Ga 0.3 ͒ 0.5 In 0.5 P cladding layer was found by the excitation mode using the wavelengths of 543.5 and 632.8 nm. Spatially resolved near-field optical spectra of both stimulated and spontaneous emissions were acquired as well. Longitudinal modes of the stimulated emission of laser diode were observed locally.

show abstract

mentioning

confidence: 99%

Optical characterization of visible multiquantum-well semiconductor lasers by collection/excitation modes of scanning near-field optical microscopy

Tsai

Chang

et al. 1999

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Spiral type electromagnetic field distribution symmetry was experimentally observed in the proximity of metallized nanocylinders, which is unexpected from experimental and theoretical (including FDTD computation of electromagnetic field distrubution) points of view. 6. ACKNOWLEGEMENTS…”

Section: Experimental Setup and Shear Force Measurements Resultsmentioning

confidence: 97%

<title>Local optical diagnostics of nanostructures: SNOM investigation of the electromagnetic field interaction with the nanostructures</title>

et al. 2004

View full text Add to dashboard Cite

Experimental and calculated results of the investigation of electromagnetic field distribution including its polarization characteristics in the vicinity of the nanostructures are presented. Experimental investigation was realized by aperture type scanning near field optical microscopes (SNOM) which operated in collection mode and provided both high spatial resolution and large scanning range. Shear force detection was used for the control of aperture to surface gap. Normal resolution which allows resolving 0.3 nm height surface steps was demonstrated for this gap control system. Theoretical computation of electromagnetic field distribution was realized by finite-difference time-domain (FDTD) method. Experimental three-dimensional maps of intensity and polarization distribution as result of light diffraction at nanoaperture in metal screen, dielectric and metallized nanocylinders were obtained. The qualitative difference between the orthogonal polarized component distributions near nanoaperture in aluminium screen was experimentally shown. The electromagnetic field concentration in the proximity of the dielectric nanocylinders was observed. This observation gives good fit with the results of FDTD computations. Spiral type electromagnetic field distribution pattern was experimentally observed in the proximity of metallized nanocylinders, which is unexpected from both experimental and theoretical points of view.

show abstract

“…9 The intensity values of the pixels of every row of the light line image are represented as: (x 1 , z 1 ), (x 2 , z 2 ), (x 3 , z 3 ), …, (x n , z n ), where x i is the pixel position, and z i is the pixel intensity, for i50,1,2, 3, …, n. A simple way to represent these intensity values is a Gaussian function. The equation of a Gaussian function is…”

Section: Light Line Image Processingmentioning

confidence: 97%

Shape detection using light line and Bezier approximation network

Rodríguez¹,

Rodrı́guez-Vera²,

Asundi³

et al. 2007

The Imaging Science Journal

View full text Add to dashboard Cite

A technique for measuring the object shape is presented. In this technique, the object is scanned by means of a light line. From the scanning, a set of images is captured by a CCD camera. The object surface is recovered by processing these images. To determine the surface dimensions, a Bezier approximation network is applied. This approximation network is constructed using information on images of a light line projected onto the objects, whose dimensions are known. The image data are extracted by applying the Gaussian approximation method. Using the approximation network in this technique, the surface measurement is determined by image processing, and the parameters of the set-up are avoided. In this manner, the accuracy of the techniques of light line projection for shape detection is improved, because errors in the parameters of the set-up are not introduced into the system. This technique has great potential, because it is a very simple experimental set-up and inexpensive. The experimental results obtained by this technique are verified with a contact method.

show abstract

Beam divergence and waist measurements of laser diodes by near-field scanning optical microscopy

Abstract: Reflection scanning near-field optical microscopy with uncoated fiber tips: How good is the resolution really?

Cited by 49 publications

References 7 publications

Optical characterization of visible multiquantum-well semiconductor lasers by collection/excitation modes of scanning near-field optical microscopy

Optical characterization of visible multiquantum-well semiconductor lasers by collection/excitation modes of scanning near-field optical microscopy

<title>Local optical diagnostics of nanostructures: SNOM investigation of the electromagnetic field interaction with the nanostructures</title>

Shape detection using light line and Bezier approximation network

Contact Info

Product

Resources

About