Inspection of periodically poled waveguide devices by confocal luminescence microscopy

• Published in: Applied physics. B, Lasers and optics Vol. 78; no. 3-4; pp. 363 - 366
• Main Authors: DIEROLF, V, SANDMANN, C
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-02-2004
• Subjects: Applied sciences; Circuit properties; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Confocal; Devices; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Domain walls; Electric, optical and optoelectronic circuits; Electronics; Emission; Emission analysis; Erbium; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Integrated optics. Optical fibers and wave guides; Microscopy; Niobates, titanates, tantalates, pzt ceramics, etc; Nonlinear optics; Nonlinear waveguides; Optical and optoelectronic circuits; Optical parametric oscillators and amplifiers; Optics; Physics; Waveguides; Lithium niobate; Poled material; Non linear optics; Erbium III; Doped materials; Confocal microscopy; Experimental device; Experimental study; Waveguide; Periodic structure; Erbium addition; Raman spectrometry; Spatial resolution
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-003-1377-2

Using confocal defect-luminescence microscopy, we investigated Er-doped periodically-poled LiNbO3 waveguide devices and found that the Er ion and vibrational Raman modes can be used effectively as probes to inspect and characterize the devices with high spatial resolution, non-destructively, and free of topographical artifacts. The technique is based on scanning over the sample, while simultaneously measuring and evaluating the emission or Raman spectra in terms of their moments (i.e., area, average emission wavelength, and spectral width). The contrast is observed even in tempered samples because of differences in intrinsic electric (strain) fields and defect arrangements that occur in regions inside and outside the waveguide as well as in regions in which domains have been inverted, or which are as grown. Evaluating different parts of the Er spectra and/or using different moments, different aspects of the device can be highlighted and regions inside and outside the waveguide, in which domains have been inverted or not inverted, as well as domain walls, can be identified. Raman spectroscopy is less sensitive, but it still can identify the domain wall regions.