Chemical Wet Etching of an Optical Fiber Using a Hydrogen Fluoride-Free Solution for a Saturable Absorber Based on the Evanescent Field Interaction

MOCVD deposition of zinc and bismuth chalcogenides films on the surface of silica optical fibres

“…First, the protecting polymer coating was uncovered on the section of a silica fibre SMF28 of a length of 2-10 mm and then the fibre was mounted on the board with a fluoroplastic covering. For fibre etching we used a non-toxic solution NH 4 F + (NH 4 ) 2 SO 4 + Н 2 O [17]. The bare section of the fibre was immersed for 3 h in 1 ml of the freshly prepared solution; the hydrophobic surface of the fluoroplastic did not allow the solution to extend.…”

“…1. sition of bismuth chalcogenides by MOCVD (up to 40 in the case of Bi 2 Se 3 ) are necessary in order to realize films with Bi 2 Se 3 , Bi 2 Te 3 stoichiometry and to avoid the deposition of numerous phases of the homologous series nBi 2 •mBi 2 Se 3 and nBi 2 •mBi 2 Te 3 , where n and m are integers [17,18].…”

“…Therefore, to form thin continuous films, it is necessary to neutralize the free bonds on the substrate surface. For this, a number of approaches are used; in particular, a two-stage process of low-temperature nucleation [19] and deposition of buffer layers of various selenides, including ZnSe [17] and ZnTe [18]. As we noted above in Section 2, the low temperature MOCVD deposition of Bi 2 Se 3 and Bi 2 Te 3 films leads to the formation of numerous phases with other stoichiometries.…”

“…But an asymmetric design of such a device causes unwanted polarization losses, which can be avoided by reducing the interaction length or using the tapered fibres [14]. According to the method of fabrication, the latter are divided into fused fibre tapers [15] and chemically etched fibre tapers [16].…”

Femtosecond mode-locking of a fiber laser using a CoSb3-skutterudite-based saturable absorber

“…Saturable absorption allows for a more stable mode-locking operation compared with NPR under changing environmental conditions. Until now, saturable-absorption properties have been identified for a variety of optical materials; for example, III-V compound semiconductors [4], carbon nanotubes (CNTs) [5][6][7][8][9], graphene [10][11][12][13][14][15], graphene oxide (GO) [16][17][18][19][20], graphite [21][22][23], topological insulators (TIs) [21][22][23][24][25][26][27][28][29][30][31][32], transition metal dichalcogenides (TMDCs) [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47], gold nanoparticles [48]…”