Laser properties of pyrromethene dyes in sol–gel glasses

Nanoimprint Lithography on Silica Sol–Gels: A Simple Route to Sequential Patterning

“…In that respect, inorganically cross-linked sol-gel (ICSG) resists appear as very attractive materials, due to their low initial viscosity and outstanding thermal, chemical, and mechanical stability. [10,11] Very few previous studies have addressed the imprinting of such materials. [12,13] In the present paper, we report the imprinting of square silica structures from simple line gratings, and demonstrate how the specific thermo-rheological behavior of ICSG resists can be harnessed to form complex structures by sequential imprinting at low pressures.…”

Synthetic Strategies for Hybrid Materials to Improve Properties for Optoelectronic Applications

“…Four signals at À42, À50, À59, and À67 ppm were observed for each hybrid matrix assayed and their assignment is based on previous studies on silica gel. [7] Using the symbol T n to design the number of silicon atoms with n siloxane bonds (n ¼ 0, 1, 2, or 3), the peak T 0 at À42 ppm corresponds to non-condensated silicon atoms represented as -CH 2 Si(OH) 3 while the peak T 1 at À50 ppm corresponds to a silicon atom bonded to two -OH groups and one siloxane group, represented by -CH 2 Si(OH) 2 O-. The peak T 2 at À59 ppm is related to the presence of a two siloxane groups bonded to the inorganic structure of type -CH 2 SiOHO 2 -, and finally, the T 3 peak at À67 ppm is associated with silicon bonded to three siloxane groups, such as -CH 2 SiO 3 -.…”

“…[1,2] Moreover, the quality of the Si-O-Si network is excellent in terms of transparency and thermal and chemical stability, resulting in stable materials with chemical and physical properties well defined, which nevertheless can be modified by a judicious choice of the organic and inorganic components. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] One of the synthesis routes of these hybrid materials is based on the simultaneous and ''in situ'' sol-gel process of the inorganic part, catalyzed in an acid media, and the free radical polymerization of the organic monomer part. These hybrid materials exhibit attractive features and unique properties to be used as hosts for organic dyes acting as active media in solid-state dye lasers, [8][9][10][11][12][13][14][15][16][17][18][19][20][21] since they combine the excellent thermal properties of inorganic glasses [22][23][24][25] with the excellent optical properties and dye compatibility of polymeric materials.…”

Electronic spectroscopy, stimulated emission, and persistent spectral hole burning of cryogenic nitrogen matrices doped with tetrabenzoporphin

“…The literature describes studies of thin 1 μm silica gel slabs doped with dyes of different classes (rhodamines, oxazole derivatives, coumarins, porphyrins, etc.) showing lasing characteristics [1][2][3][4][5][6]. It is important to note that in some experiments [3,5] external optical resonator mirrors were missing and stimulated emission (SE) was nevertheless detected due to light amplification in a single pass through the layer by just a "traveling wave" (traveling lasing wave).…”