Fabrication of highly nonlinear germano-silicate glass optical fiber incorporated with PbTe semiconductor quantum dots using atomization doping process and its optical nonlinearity

Abstract

Germano-silicate glass optical fiber incorporated with PbTe semiconductor quantum dots (SQDs) in the core was fabricated by using the atomization process in modified chemical vapor deposition (MCVD) process. The absorption bands attributed to PbTe semiconductor quantum dots in the fiber core were found to appear at around 687 nm and 1055 nm. The nonlinear refractive index measured by the long-period fiber grating (LPG) pair method upon pumping with laser diode at 976.4 nm was estimated to be ~1.5 × 10(-16) m2/W.

Dependence of beating dynamics on the ellipticity of a Gaussian beam in graded-index absorbing nonlinear fibers

“…(9)-(14) for the saturable model and Eqs. (9)- (13) and (15)-(17) for the cubic-quintic model to find η 1,2 as a function of propagation distance, ξ . To compare the solution with that for cylindrical beam, we defined initial conditions as A 2 (0)a 1 (0)a 2 (0) = A 2 r (0)a 2 r (0), a 2 (0) = ρa 1 (0), and b 1,2 (0) = c 1,2 (0) = φ(0) = 0.…”

“…For typical fiber materials, the Kerr coefficient is of the order 5 × 10 −15 -5 × 10 −16 cm 2 /W, and thus the critical intensity for self-focusing is of the order 0.44 − 4.4 MW/cm 2 for a wavelength of 1.5 μm [10]. In contrast, some new optical materials are characterized by Kerr coefficients of the order 10 −11 -10 −12 cm 2 /W [11][12][13], making the critical intensity for self-focusing four orders of magnitude smaller so that it can be reached using microsecond pulses and possibly even CW laser beams. The (linear and nonlinear) absorption coefficients of these materials are higher compared to those of typical fibers, and the propagation of laser beams through such media is of great interest.…”

Statistics of modifier distributions in mixed network glasses

“…[13][14][15][16][17] In the medical field, phosphosilicate glasses are widely used for their bioactive properties such as the natural stimulation of bone growth. [18][19][20][21] Other mixed network glasses of particular note include titanosilicate glasses for applications requiring ultra-low thermal expansion, [22][23][24][25][26] germanosilicate glasses for specialized optical applications, [27][28][29] and borophosphate glasses for fast ion conduction. [30][31][32] In each of these cases, optimized glass compositions can be designed to maximize the benefit of each network former species.…”

Crystallization Behaviors of PbSe Quantum Dots in Silicate Glasses

“…Quantum dots (QDs), also known as semiconductor nanocrystals, have attracted considerable attention in the past few years due to their peculiar and fascinating properties, and applications superior to their bulk counterparts . IV–VI semiconductor QDs of lead chalcogenides, for instance, PbS and PbSe are excellent candidates for optical communication applications because of their narrow band gaps, large optical nonlinearity, and fast response time . Moreover, compared with II–VI and III–V QDs whose exciton Bohr radii ( a B ) are typically ~10 nm or more, while the Bohr radius of the hole is only ~1 nm due to the large difference between the electron and the hole effective masses, the QDs of lead chalcogenide almost possess equally small effective masses between electron and hole (e.g., m e ≈ m h ≈ 0.1 for PbS and m e ≈ m h ≈ 0.05 for PbSe) and the large optical dielectric constants (e.g., ε ∞ = 18 for PbS and ε ∞ = 22 for PbSe), which results in relatively large effective electron, hole, and exciton Bohr radii (e.g., a h = a e =10 nm and a B = 20 nm for PbS; a h = a e = 23 nm and a B = 46 nm for PbSe) .…”