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Abstract. A comparative study of Nd:GdVO[sub 4] and Nd:YVO[sub 4] crystal lasers pumped by a cw diode laser has been conducted at the fundamental wavelengths of 1.06 micro m and 1.34 micro m, as well as when intracavity frequency-doubled to 532 nm and 670 nm, respectively. At these four wavelengths, maximum output powers from the Nd:GdVO[sub 4] crystal laser were 1.27 W, 800mW, 610mW, and 82mW at a diode-launched pump power of 2.9 W. The threshold pump powers were 64 mW, 159 mW, 5 mW, and 12 mW, respectively. All the results obtained from Nd:GdVO[sub 4] were superior to those of Nd:YVO[sub 4], indicating that Nd:GdVO[sub 4] is a more efficient laser crystal than Nd:YVO[sub 4] for diode-pumped solid-state lasers. [ABSTRACT FROM AUTHOR]

A Nd3+ doped La3Ga5.5Ta0.5O14 (Nd:LGT) crystal has been grown by the Czochralski method for the first time. Absorption spectrum and fluorescence spectrum has been measured and the results show Nd:LGT crystal may emit 1064 nm wavelength laser when a laser-diode of 808 nm is used as pumping source. The laser experiment indicates the output power of Nd:LGT is 130 mW when the incident pumping power is 2.2 W. [Copyright &y& Elsevier]

Abstract: In this paper, we propose, analyze and demonstrate a high-purity float-zone (FZ) silicon phototransistor operating at the punch through state with high linearity and sensitivity. Those phototransistors were fabricated on high-purity FZ silicon substrates; the dependence of the sensitivity on incident optical power and bias voltages has been investigated to light with a wavelength of 0.83μm from a laser diode. In accordance with theoretical prediction, it shows that the linearity reaches the highest when the base of the phototransistor is completely depleted (punch through), and the fitting goodness of output R 2 is 0.9954 over a 40dB range from 0.15 to 1500nW. The sensitivity of the phototransistor can be as large as 40–70A/W at the punch through state, which is equivalent to an internal current conversion gain of about 75–130. The stability of 1% in the sensitivity for the punch through phototransistor with an internal current conversion gain of 130 can be obtained if the bias voltage and operating temperature can be stable to about 2.5% (1 in 40V) and the temperature to ±2°C. [Copyright &y& Elsevier]

Abstract: New data relating to flux growth, composition, homogeneity and physical characteristics of (R,Y)Al3(BO3)4 (R=Tm or Yb) crystals are discussed. Single crystals have been obtained using K2Mo3O10-based fluxes by spontaneous nucleation as well as by the top-seeded solution growth at cooling rates of 4.8–12°C/day and 0.2–5°C/day, respectively, in the temperature range from 1120 to 900°C. It is found that the average Tm and Yb segregation coefficients are close to unity, and vary from 0.80 to 1.02, as a consequence of minor difference in the sizes between Y3+ and R3+ cations. Two morphological types of (Tm,Y)Al3(BO3)4 crystals have been revealed. The average thermal expansion coefficients of Yb:YAB along a- and c-axis are measured as 2×10−6/K and 9.7×10−6/K, respectively, in the temperature range of 298–573K. The specific heat of the Yb:YAB crystal at room temperature is found to be 0.76J/gK, implying that this material can exhibit significant resistance to laser damage. Over 1.1W of green emission has been obtained from a diode pumped 3×3×3mm3 Yb:YAB crystal. The conversion efficiency of diode to green is 10%. High beam quality of green and IR emission can be easily attained due to the good crystal quality and lack of thermal effects. [Copyright &y& Elsevier]

Abstract: We have experimentally demonstrated an efficient diode pumped Tm:CLNGG disordered crystal laser operating at 2μm wavelength. The maximum output power of 1.6W was obtained with a slope efficiency as high as 37%. The spectrum of the free-running disordered crystal laser shows a wide emission bandwidth, which will benefit to ultrashort pulse generation by mode locking. Our results suggest that the Tm:CLNGG disordered crystal is a potential laser material for generation of ultrashort pulses at 2μm wavelength. [Copyright &y& Elsevier]

Abstract: Passive mode-locking of a diode-pumped Nd:CLNGG laser was demonstrated for the first time to our knowledge. The laser operated at a central wavelength of 1061.2nm with a maximum average output power of 101mW. The mode-locked pulses have pulse duration of 2.0ps, a spectral bandwidth of 1.2nm and a repetition rate of 88.4MHz. The mode locking of the laser was enabled by a semiconductor saturable absorber mirror (SESAM). [Copyright &y& Elsevier]

Abstract: Passive mode-locking of a diode pumped Yb-doped GdVO4 crystal laser was demonstrated for the first time to our knowledge. The laser was mode-locked at the wavelength of 1019.1nm and had an average output power of 1.01W. The mode-locked pulse duration was 3.1ps. The laser was end-pumped by a high-power fiber pigtailed laser diode bar and the mode-locking was enabled by a semiconductor saturable absorber mirror (SESAM). [Copyright &y& Elsevier]