Supercontinuum Generation over 2 µm

Effective supercontinuum generation in fiber mediain spectral range over 2 μm was experimentallydemonstrated. Supercontinuum generation wasobserved in passive optical fibers. Maximumspectral broadening was obtained in germaniumdopedfibers with longest wavelength near 2.7 μm.To provide high spectral density we used opticalfiber amplifiers. Thus supercontinuum generationwas obtained in holmium optical fiber amplifiersmedium with spectral density 10 W/nm, in therange from 2 to 2.5 μm. In thulium fiber amplifiersobserved amplification not only in conventionalrange near 1.8 μm, but in spectral range from 2.3 to2.5 μm, that corresponds to 3H4→ 3H5 opticaltransition possibility in thulium-doped opticalfibers

Pulsed laser deposition of thin YBCO films on faceted YSZ single crystal fibers

Flexible rods of single crystals of 9% Y2O 3-stabilized ZrO2 (YSZ) were used as substrates for deposition of high-critical temperature superconducting (HTS) thin films. YSZ fibers were prepared by mini-pedestal method with laser heating and had average diameter of 300 micrometers and 30 mm length. X-ray diffraction analysis demonstrated high crystalline quality of obtained fibers and also indicated the presence of 15° deviation of the fiber axis from the [001] YSZ direction. Thin YBa2Cu3O7-x films were grown by pulsed laser deposition on YSZ rods using CeO2 buffer layer. Films have shown high critical temperature of 90 K with sharp superconducting transition. Critical current density was estimated to about 3×104 A/cm 2 at 80 K. Temperature dependence of critical current density suggests granular structure of films with grain size about several microns. Our results demonstrate feasibility of flexible YSZ fibers coated by HTS thin films for practical use

Comparison of Continuous Wave and Ultrashort Pulsed Holmium-doped Fiber Lasers Exposure on Ex-vivo Tissue

Holmium (Ho 3+ ) laser systems emitting in the spectral range of 2-2.1m are widely used in many medical fields: urology, dermatology, surgery, and etc. This is due to the high absorption of laser radiation by water contained in soft tissues. It is of interest to compare the efficiency of soft tissue ablation using 2m lasers operating in continuous wave (CW) and ultrashort pulsed modes. In previous studies the Tm-doped fiber laser [1], Tm:YLF and Ho:YAG lasers [2] exposure have compared. © 2021 IEEE

Импульсный волоконный гольмиевый лазер с внутрирезонаторным интерферометром Маха-Цандера

A scheme of a fully fiber holmium (Ho) laser with active Q-switching and lasing at wavelength of 2100 nm was realized. The effect of changing the reflection coefficient of the output mirror of the resonator (4, 10, 20 %) on the laser pulse duration is shown. A minimum pulse duration of 0.64 μs was obtained in a scheme with an output Bragg grating having a reflection coefficient of 20 %.Реализована схема полностью волоконного гольмиевого лазера с активной модуляцией добротности и генерацией на длине волны 2100 нм. Показано влияние изменения коэффициента отражения выходного зеркала резонатора (4, 10, 20 %) на длительность импульса. Получена минимальная длительность импульса 0,64 мкс в схеме с коэффициентом отражения выходной брэгговской решетки 20 %