Zhonghong Jiang

Upconversion emission in multi-doped glasses for full colour display

Upconversion luminescence characteristics of a multi-rare-earth-doped 0.05K2O?0.1ZnO?0.1BaO?0.2PbO?0.2GeO2?0.35TeO2 glass have been investigated under 976?nm excitation for potential use in full colour displays. Two luminescence ions, Er3+ and Tm3+, were used as blue, green and red emitters to control the colour of the emitted light. Sensitizer ions, Yb3+, were used to increase the upconversion emission intensity. With the substitution of Er3+ for Tm3+, the intensities of the blue, green and 657?nm upconversion emissions simultaneously increase.

10.9 W kHz-linewidth one-stage all-fiber linearly-polarized MOPA laser at 1560 nm

An all-fiber 10.9 W single-frequency one-stage linearly-polarized master-oscillator power amplifier (MOPA) laser at 1560 nm has been demonstrated. The laser linewidth is less than 3.5 kHz and the polarization-extinction ratio (PER) is greater than 24 dB. The measured signal-to-noise ratio (SNR) is higher than 70 dB and the optical-to-optical conversion efficiency is 29.5%. No obvious stimulated Brillouin scattering and the devastating effects of unwanted coupling light were observed.

Slow/fast light using a very short Er 3+ /Yb 3+ co-doped fiber

A slow/fast light device with a sealed size of 130 mm×30 mm×3 mm has been demonstrated. Ultraslow propagation and superluminal propagation with group velocity values from 8.4 to -14.7 m/s are observed in a 3.86 cm long Er3+/Yb3+ co-doped single-mode phosphate glass fiber. The dependence of pump power, modulation frequency, and wavelength on the slow/fast light effect in this fiber is investigated in detail. These results suggest that this compact slow/fast device is more suitable for all-fiber applications than those made by traditional methods.

Spectroscopic properties and energy transfer of Tm3+/Ho3+-codoped TeO2–WO3–ZnO glasses for 1.47 μm amplifier

We report on spectroscopic properties and energy transfer of Tm(3+)/Ho(3+)-codoped tungsten tellurite glasses for 1.47microm amplifier. Fluorescence spectra and the analysis of energy transfer indicate that Ho(3+) is an excellent codopant for 1.47microm emission. Comparing with other tellurite glasses, the radiative lifetime of the (3)H(4) level of Tm(3+) in tungsten tellurite glass is slightly lower, but the spontaneous emission probability, stimulated emission cross-section and the figure of merit for bandwidth are obviously larger. Although the pump efficiency of tungsten tellurite amplifier is approximately 50% less than that of fluoride glass, the figure of merit for bandwidth is approximately three times larger in tungsten tellurite glass than in fluoride glass. The results indicate that Tm(3+)/Ho(3+)-codoped tungsten tellurite glass is attractive for broadband amplifier.

High-efficiency watt-level 1014 nm single-frequency laser based on short Yb-doped phosphate fiber amplifiers

High-efficiency single-frequency compact master-oscillator power amplifiers (MOPAs) based on core-pumped highly Yb-doped phosphate fibers (YPFs), several centimeters long, are investigated theoretically and experimentally. By using numerical modeling and testing different YPF lengths to optimize the amplifier configuration, a stable output of more than 1.06 W, at 1014 nm, was measured experimentally from a MOPA laser, with a 4.0 cm long YPF. An optical-to-optical conversion efficiency of 81.4%, a typical net gain of more than 20.5 dB, and an output power per unit length of up to 265 mW/cm were obtained with this laser system. The measured optical signal-to-noise ratio of the MOPA laser is higher than 62 dB and the estimated laser linewidth is less than 20 kHz, without obvious broadening or degradation after amplification. There is excellent agreement between the results of the simulations and the experiments.

Photo-induced refractive index change of bismuth-based silicate glass

We report the ultraviolet laser-induced absorption spectra and refractive index changes in bismuth-based silicate glass. A positive maximum refractive index change of 6×10 −4 has been observed in bismuth-based silicate glass upon exposure to a pulsed 248 nm KrF excimer laser. It is also seen that the changes in the absorbance and refractive index are strongly dependent on glass melting conditions.

High OSNR watt-level single-frequency one-stage PM-MOPA fiber laser at 1083 nm.

A 1.03 W optical signal-to-noise ratio (OSNR) of > 70 dB single-frequency polarization-maintained master-oscillator power amplifier (PM-MOPA) laser at 1083 nm was demonstrated. The seed laser of this laser system was a distributed Bragg reflector short cavity Yb-doped phosphate fiber oscillator. A one-stage core-pumped amplification configuration was employed, in which the typical gain is 9.7 dB and the optical-to-optical conversion efficiency is 68.7%. The estimated laser linewidth is less than 3.5 kHz, the measured polarization-extinction ratio is greater than 25 dB, and the obtained relative intensity noise of fiber laser for frequencies of over 2 MHz is less than -130 dB/Hz.

Spectral properties and energy transfer of Tm3+/Ho3+-codoped Ga2O3-Bi2O3-GeO2-PbO glasses

Abstract The 2.0 μm emission originating from Ho 3+ : 5 I 7 → 5 I 8 transition in Ho 3+ /Tm 3+ -codoped gallate-bismuth-germanium-lead glasses were investigated upon excitation with 808 nm laser diode (LD). Energy transfer (ET) process between Tm 3+ : 3 F 4 level and Ho 3+ : 5 I 7 level was also discussed. It was noted that the measured peak wavelength and stimulated emission cross-section of Ho 3+ -doped bismuth-germanium-lead glasses were ∼2.02 μm and 5.1×10 −21 cm 2 , respectively. Intense emission of Ho 3+ in Tm 3+ /Ho 3+ -codoped GBPG glass were observed, which resulted from the ET between Tm 3+ : 3 F 4 and Ho 3+ : 5 I 7 level upon excitation with 808 nm LD.

Ultra Compact Kilohertz-Linewidth High-Power Single-Frequency Laser Based on Er3+/Yb3+-Codoped Phosphate Fiber Amplifier

An all-fiber and ultra compact master-oscillator power amplifier (MOPA) employing a bidirectionally core-pumped 4-cm-long Er3+/Yb3+-codoped phosphate fiber has been demonstrated experimentally. An over 600 mW stable single-frequency amplification laser was generated at 1535 nm without appreciable degradation of seed laser characteristics. The measured MOPA laser linewidth is less than 2 kHz, the signal-to-noise ratio (SNR) is higher than 65 dB, and the relative intensity noise (RIN) is -160 dB/Hz for frequencies above 2.0 MHz. The optical-to-optical conversion efficiency is 42.9%, and the output power per unit fiber length is up to 152 mW/cm.