130-km-long fault location for single-mode optical fiber using 1.55-microm Q-switched Er(3+):glass laser

Research Progress and Development of Near-Infrared Phosphors

Near-infrared (NIR) light has attracted considerable attention in diverse applications, such as food testing, security monitoring, and modern agriculture. Herein, the advanced applications of NIR light, as well as various devices to realize NIR light, have been described. Among the diverse NIR light source devices, the NIR phosphor-converted light-emitting diode (pc-LED), serving as a new-generation NIR light source, has obtained attention due to its wavelength-tunable behavior and low-cost. As one of the key materials of the NIR pc-LED, a series of NIR phosphors have been summarized depending on the type of luminescence center. Meanwhile, the characteristic transitions and luminescence properties of the above phosphors are illustrated in detail. In addition, the status quo of NIR pc-LEDs, as well as the potential problems and future developments of NIR phosphors and applications have also been discussed.

Single-pass mode-locked or Q-switched pump operation of D2 gas-in-glass fiber Raman lasers operating at 1.56-microm wavelength

Single-pass operation of a D(2) gas-in-glass fiber Raman laser operating at 1.56-microm wavelength, pumped by a Nd: YAG laser operating either Q-switched or mode-locked has been demonstrated. The group velocities in the single-mode host fiber at the pump wavelength (1.06 microm) and the Raman-shifted wavelength (1.56 microm) were matched, thereby providing long interaction lengths and concomitant efficient conversion of pump light to 1.56-microm radiation.