A novel polymer-modified PbS quantum dot (QD) optical fiber amplifier was proposed and demonstrated. It was fabricated by depositing a PbS QD doped film around the tapered single mode fiber (SMF) coupler. The PbS QDs were synthesized in an organic phase and then transfer into water by polymer modification. A 1550 nm semiconductor light emitting diode as the signal source and a 980 nm laser diode source as the pump were injected into the fiber coupler simultaneously. Through evanescent wave excitation, we obtained a significant gain of about 6dB within the wavelength range between 1450 and 1650 nm.
Silver nanoparticles have been found many interesting applications, such as absorption amplifiers in dye-sensitized solar
cells. However, silver nanoparticles are easily oxidized. In order to protect silver nanoparticles, atomic layers of TiO<sub>2</sub>were deposited onto silver nanoparticles coated to a glass slide. Then the glass slide was exposed to corrosive I<sup>-</sup>/I<sub>3</sub><sup>-</sup> solutions, and the degree of silver etching was measured via scanning electron microscopy (SEM) and ultraviolet-visible
spectroscopy (UVS). It was found that 3 nm (30 cycles) of Al<sub>2</sub>O<sub>3</sub> with 9 nm of (90 cycles) TiO<sub>2</sub> could completely protect
silver nanoparticles from oxidization.
A novel PbS quantum dots (QDs) fiber amplifier based on SiO<sub>2</sub> Sol-Gel method was proposed. The QDs doped
SiO<sub>2</sub> films was deposited onto a fused tapered fiber coupler based on standard single mode fiber (SMF). With a 980 nm
wavelength laser diode (LD) as the pump, 1550 nm signal and 980 nm pump light waves were injected into the tapered
region simultaneously, through the evanescent wave, we obtained the gain at 1576 nm wavelength as high as 5 dB. The
proposed fiber amplififier can implement the property of a small, integrated, high output, low noise, high gain, low cost,
which meet the need of the future of optical fiber communication system.
A PbSe quantum dots (QDs) fiber amplifier has been demonstrated. The PbSe QDs were synthesized via sol-gel self-assembly
method. The size of PbSe QDs was controlled to 5.5 nm through control of the reaction time as well as the
growth temperature. Transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy were used to
characterize the PbSe QDs samples. The fiber amplifier was fabricated by coating the QDs onto a tapered optical fiber
coupler. Through evanescent wave, the QDs were excited to realize optical amplification. A 1550 nm semiconductor
light emitting diode (SLED) as the signal source and a 980 nm laser diode (LD) source as the pump were injected into
the fiber coupler simultaneously.