Photochemical Deposition of Transparent Low Refractive Index SiO2 Topcoat for Laser Head at Room Temperature

2004 ◽  
Vol 843 ◽  
Author(s):  
Y. Tezuka ◽  
M. Murahara
Keyword(s):  
Refractive Index ◽  
Evanescent Wave ◽  
Room Temperature ◽  
Visible Region ◽  
Antireflection Coating ◽  
Mixed Gas ◽  
Laser Head ◽  
Photochemical Deposition ◽  
Glass Slab ◽  
Low Refractive Index

ABSTRACTA transparent, low refractive index SiO 2 film was photo-chemically laminated on a glass slab laser head by the Xe2* excimer lamp in the atmosphere of NF3 and O2 mixed gas at room temperature; which made it possible to inhibit the decrease in the laser output power caused by the evanescent wave leakage.The transparent SiO2 film of 260nm thickness was laminated on the non-heated substrate by the lamp irradiation for one hour. The hardness of the film before annealing was 3 by Mohs’ Scale of Hardness, and its hardness improved to 5 after annealing at 250 degrees centigrade for one hour. The refractive index of the film was 1.42, being lower than the index of silica glass that is 1.46. Furthermore, the transmittance in the visible region increased by 2% with it s antireflection coating.

Anti–scatter coating on slab laser head for preventing evanescent wave by photo–oxidation of silicone oil

2005 ◽  
Vol 890 ◽  
Author(s):  
Takayuki Funatsu ◽  
Nobuhiro Sato ◽  
Yuji Sato ◽  
Takayuki Okamoto ◽  
Masataka Murahara
Keyword(s):  
Thin Film ◽  
Refractive Index ◽  
Evanescent Wave ◽  
Room Temperature ◽  
Silicone Oil ◽  
Total Reflection ◽  
Excimer Lamp ◽  
Laser Head ◽  
Slab Laser ◽  
Low Refractive Index

ABSTRACTA low refractive index, hard SiO2 film was photochemically coated on the surface of slab laser head at room temperature by using silicone oil and a Xe2 excimer lamp. Nd+:glass slab laser produces high power laser because the light is amplified with a repeated total reflection in the laser medium. However, an evanescent wave arises on the total reflection interface, which causes a loss of the light energy. A low refractive index film 2 μm thick is, therefore, needed to prevent this problem. The vacuum vapor deposition method as a dry process and the spin-coating method as a wet process are generally used for making optical thin films. The former method can laminate a hard thin film, but requires temperatures above 500°C, and the thermal denaturation of the optical substrate is unavoidable. On the other hand, the latter method can form a low refractive index thin film, but the produced thin film has a poor adhesiveness and a low hardness. Besides, all these films are inferior in water resistance. We, therefore, formed a water-resistant, hard, and low refractive index protective coating directly on the laser glass surface at room temperature with photochemical reaction by the Xe2 excimer lamp.

Photochemical Lamination of Low Refractive Index Transparent SiO2 Film at Room Temperature for Antireflection Coating

2002 ◽  
Vol 750 ◽  
Author(s):  
Y. Ogawa ◽  
M. Murahara
Keyword(s):  
Refractive Index ◽  
Room Temperature ◽  
Antireflection Coating ◽  
Sio2 Film ◽  
Fused Silica ◽  
Photochemical Reactions ◽  
Atom Density ◽  
Reflection Of Light ◽  
Fused Silica Glass ◽  
Low Refractive Index

ABSTRACTA transparent low refractive index SiO2 film laminated on a glass substrate at room temperature by photochemical reactions with the Xe2* excimer lamp (172nm). This SiO2 film grown on the fused silica glass was proved to avoid reflection of light.A refractive index of the SiO2 film was 1.36. After annealing the film for one hour at 200 degrees centigrade, the refractive index increased to 1.42. The refractive index increased as the F atom density in the SiO 2 film decreased.

Waveguide Capillary Cell for Low-Refractive-Index Liquids

1997 ◽  
Vol 51 (10) ◽  
pp. 1554-1558 ◽  
Author(s):  
Robert Altkorn ◽  
Ilia Koev ◽  
Amos Gottlieb
Keyword(s):  
Refractive Index ◽  
Thin Layer ◽  
Reflection Loss ◽  
Total Internal Reflection ◽  
Visible Region ◽  
Fused Silica ◽  
Internal Reflection ◽  
Silica Tube ◽  
Transparent Liquid ◽  
Low Refractive Index

We describe a waveguide capillary cell based on a fused-silica tube coated externally with a thin layer of a low-refractive-index ( n = 1.31) fluoropolymer. When filled with a transparent liquid of refractive index greater than that of the fluoropolymer, the cell is capable of transmitting light through total internal reflection. Loss below 1 dB/m is demonstrated throughout much of the visible region for a 530-μm-i.d., 660-μm-o.d. cell filled with water.

Nanostructured Transparent Conductive Oxides for Photovoltaic Applications

2013 ◽  
Vol 1493 ◽  
pp. 23-28 ◽  
Author(s):  
Roger E. Welser ◽  
Adam W. Sood ◽  
Jaehee Cho ◽  
E. Fred Schubert ◽  
Jennifer L. Harvey ◽  
...  
Keyword(s):  
Refractive Index ◽  
Indium Tin Oxide ◽  
High Performance ◽  
Antireflection Coating ◽  
Back Surface ◽  
Oblique Angle Deposition ◽  
Wide Range ◽  
Photovoltaic Applications ◽  
Angle Deposition ◽  
Low Refractive Index

ABSTRACTOblique-angle deposition is used to fabricate indium tin oxide (ITO) optical coatings with a porous, columnar nanostructure. Nanostructured ITO layers with a reduced refractive index are then incorporated into antireflection coating (ARC) structures with a step-graded refractive index design, enabling increased transmittance into an underlying semiconductor over a wide range of wavelengths of interest for photovoltaic applications. Low-refractive index nanostructured ITO coatings can also be combined with metal films to form an omnidirectional reflector (ODR) structure capable of achieving high internal reflectivity over a broad spectrum of wavelengths and a wide range of angles. Such conductive high-performance ODR structures on the back surface of a thin-film solar cell can potentially increase both the current and voltage output by scattering unabsorbed and emitted photons back into the active region of the device.

Room-Temperature Formation of Low Refractive Index Silicon Oxide Films Using Atmospheric-Pressure Plasma

2011 ◽  
Vol 11 (4) ◽  
pp. 2851-2855 ◽  
Author(s):  
Kei Nakamura ◽  
Yoshihito Yamaguchi ◽  
Keiji Yokoyama ◽  
Kosuke Higashida ◽  
Hiromasa Ohmi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Silicon Oxide ◽  
Oxide Films ◽  
Atmospheric Pressure Plasma ◽  
Pressure Plasma ◽  
Low Refractive Index

scholarly journals Strong coupling of single quantum dots with low-refractive-index/high-refractive-index materials at room temperature

2020 ◽  
Vol 6 (47) ◽  
pp. eabb3095
Author(s):  
Xingsheng Xu ◽  
Siyue Jin
Keyword(s):  
Quantum Dots ◽  
Refractive Index ◽  
Strong Coupling ◽  
Room Temperature ◽  
High Refractive Index ◽  
Colloidal Quantum Dots ◽  
Rabi Splitting ◽  
Pl Spectra ◽  
Dielectric Cavity ◽  
Low Refractive Index

Strong coupling between a cavity and transition dipole moments in emitters leads to vacuum Rabi splitting. Researchers have not reported strong coupling between a single emitter and a dielectric cavity at room temperature until now. In this study, we investigated the photoluminescence (PL) spectra of colloidal quantum dots on the surface of a SiO2/Si material at various collection angles at room temperature. We measured the corresponding reflection spectra for the SiO2/Si material and compared them with the PL spectra. We observed PL spectral splitting and regarded it as strong coupling between colloidal quantum dots and the SiO2/Si material. Upper polaritons and lower polaritons exhibited anticrossing behavior. We observed Rabi splitting from single-photon emission in the dielectric cavity at room temperature. Through analysis, we attributed the Rabi splitting to strong coupling between quantum dots and bound states in the continuum in the low-refractive-index/high-refractive-index hybrid material.

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

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