Spectral, Morphological and Dynamical Analysis of a Holographic Grating Recorded in a Photo-Mobile Composite Polymer Mixture

We report on the morphological, spectral and dynamical characterization of one-dimensional transmission holographic volume phase gratings, whose refractive index contrast and nanometric pitch are dynamically controlled by an incident laser light. The grating is obtained by the photo-polymerization of a recently developed photo-mobile holographic composite polymer material. The observed changes in the refractive index contrast and grating pitch strongly suggest that the reversible all-optical real-time modulation of the obtained diffraction efficiency is induced by nano-fluidics.

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Optical and Nanomechanical Characterization of an Omnidirectional Reflector Encompassing 850 nm Wavelength

MRS Proceedings ◽

10.1557/proc-817-l5.8 ◽

2004 ◽

Vol 817 ◽

Author(s):

Manish Deopura ◽

Yoel Fink ◽

Christopher A. Schuh

Keyword(s):

Mechanical Properties ◽

Refractive Index ◽

Tin Sulfide ◽

Practical Applications ◽

Refractive Index Contrast ◽

Infra Red ◽

Index Contrast ◽

Laminate Materials

AbstractWe demonstrate that multilayers composed of nineteen alternating layers of tin sulfide and silica can function as omnidirectional reflectors. These materials exhibit omnidirectional reflectivity for a range of frequencies in the near infra-red (NIR) encompassing the 850 nm wavelength. A refractive index contrast of 2.7/1.46 is achieved, one of the highest values demonstrated until now in NIR photonic bad gaps. In addition, new nanoindentation procedures have been developed to measure mechanical properties of these fine laminate materials, and demonstrate that tin sulfide-silica multilayers are mechanically stable for practical applications.

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Optical Sensitivity of Waveguides Inscribed in Nanoporous Silicate Framework

Nanomaterials ◽

10.3390/nano11010123 ◽

2021 ◽

Vol 11 (1) ◽

pp. 123

Author(s):

Zhong Lijing ◽

Roman A. Zakoldaev ◽

Maksim M. Sergeev ◽

Andrey B. Petrov ◽

Vadim P. Veiko ◽

...

Keyword(s):

Refractive Index ◽

Near Field ◽

Experimental Studies ◽

Laser Pulses ◽

Femtosecond Laser Pulses ◽

Direct Writing ◽

Sensor Applications ◽

Refractive Index Contrast ◽

Optical Sensitivity ◽

Index Contrast

Laser direct writing technique in glass is a powerful tool for various waveguides’ fabrication that highly develop the element base for designing photonic devices. We apply this technique to fabricate waveguides in porous glass (PG). Nanoporous optical materials for the inscription can elevate the sensing ability of such waveguides to higher standards. The waveguides were fabricated by a single-scan approach with femtosecond laser pulses in the densification mode, which resulted in the formation of a core and cladding. Experimental studies revealed three types of waveguides and quantified the refractive index contrast (up to Δn = 1.2·10−2) accompanied with ~1.2 dB/cm insertion losses. The waveguides demonstrated the sensitivity to small objects captured by the nanoporous framework. We noticed that the deposited ethanol molecules (3 µL) on the PG surface influence the waveguide optical properties indicating the penetration of the molecule to its cladding. Continuous monitoring of the output near field intensity distribution allowed us to determine the response time (6 s) of the waveguide buried at 400 µm below the glass surface. We found that the minimum distinguishable change of the refractive index contrast is 2 × 10−4. The results obtained pave the way to consider the waveguides inscribed into PG as primary transducers for sensor applications.

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