Kalin Spariosu

Dual Q switching and laser action at 1.06 and 1.44 μm in a Nd 3+ :YAG–Cr 4+ :YAG oscillator at 300 K

We report what is to our knowledge the first dual operation comprising laser action and Q switching of Cr(4+):YAG pumped intracavity by a Nd:YAG laser. This technique produced dual 1.06- and 1.44-microm pulses with 35- and 200-ns pulse widths, respectively. The Nd:YAG rod was pumped by a 1-ms flash-lamp pulse, resulting in a train of 1.06- and 1.44-microm pulse pairs at approximately a 30-kHz rate.

Er:Ca5(PO4)3F saturable‐absorber Q switch for the Er:glass laser at 1.53 μm

Passive Q switching of an Er:phosphate glass laser using Er:Ca5(PO4)3F (Er:FAP) as a saturable absorber intracavity (IC) load is described for the first time. Q‐switched output was obtained consisting of a 6‐mJ single pulse of 83 ns full width at half maximum, with a 20% efficiency relative to the corresponding free‐running output in the absence of the IC Er:FAP load.

Cr4+: GSGG saturable absorber Q-switch for the ruby laser

Abstract Cr 4+ : GSGG has been utilized for the first time to provide a saturable absorber Q -switch for the ruby laser. Single output pulse operation (100 mJ and 27 ns duration) with efficiencies relative to the free-running ruby laser operation of 25–30% was routinely obtained.

U4+:SrF2 efficient saturable absorber Q switch for the 1.54 μm erbium:glass laser

Saturable absorber Q switching of the Er:glass laser at 1533 nm using U4+:SrF2 has been obtained. Q‐switched pulses of 3 mJ and 60 ns full width at half‐maximum were achieved using a 2.69‐mm‐thick Q switch in a 14‐cm‐long plane‐parallel cavity, with a 3×50 mm Kigre QE‐7S Er:glass rod. The high absorption cross section of U4+:SrF2 resulted in efficient Q‐switched operation (without intracavity focusing) in agreement with the theoretical predictions.

Er 3+ :Y 3 Al 5 O 12 laser dynamics: effects of upconversion

Room-temperature 1.532-μm pumped 1.645-μm laser action in the Er3+:Y3Al5O12(Er:YAG) 4I13/2y3 (6602-cm−1) ⇒ 4I15/2z7 (523-cm−1) transition was demonstrated and was analyzed. Laser action at 1.645 μm was achieved in Er:YAG crystals with Er concentrations ranging from 0.5% to 4%. Slope efficiencies as high as 40% were obtained with 0.5% Er:YAG. For concentrations up to 4%, measurements of laser thresholds indicate that upconversion losses were small.

Room-temperature 1.643-μm Er 3+ :Y 3 Sc 2 Ga 3 O 12 (Er:YSGG) laser

Laser operation at 1.643 µm ((4)I(13/2)-(4)I(15/2)) in Er(3+):Y(3)Sc(2)Ga(3)O(12) (Er:YSGG) at 300 K is reported. An Er:glass laser (1.532 µm) was used in an end-pumping arrangement to obtain laser output from a 1-cm-long 0.7% Er(3% Yb, 1% Cr):YSGG crystal in an external cavity. The Er:YSGG laser exhibited an 18-mJ threshold and a 10% slope efficiency.

Upconversion effects on Er:YAG laser dynamics

The 1.645 (mu) laser action in Er3+:Y3Al5O12 (Er:YAG) at 300 K was studied using the 1.532 micrometers Er:glass laser for excitation. Laser action was with Er concentrations ranging from 0.5% to 4%. Slope efficiencies as high as 40% were obtained with 0.5% Er:YAG. Laser threshold results indicated that for this Er concentration range upconversion losses were small (negligible for 0.5% Er).

Room-Temperature 1.644 Micron Er:YAG Lasers

Room temperature Er:YAG (0.5, 1, 2 and 4%) lasers at 1.644μ were demonstrated by pumping with an Er glass laser at 1.535 μ. An end pumped arrangement was utilized simulating diode laser pumping. The characteristics of these low threshold and elficient lasers are described.

Controllable high-repetition-rate 1.645 μm laser pulse pair generation for lidar applications

In this paper, we describe the temporal laser pulse dynamics of the 1.645 micrometers Er:YAG laser pumped by a 1.532 micrometers Er:glass laser. It can be shown that controllable double pulsing of the 1.645 micrometers laser action can be obtained by gain-switched type operation and a variable cavity loss. The rate equation dynamics model can predict this behavior, and thereby provide a design platform for generating controllable double pulsing outputs at high repetition rates. Applications to lidar techniques are discussed. Some innovative applications include polarization discrimination techniques in target detection technology and mitigating atmospheric turbulence effects in measurements.

Er:YSGG 1.643-μ laser at 300 K

The 4I13/2 - 4I15/2 laser action in Er3+:Y3Sc2Ga3O12 (Er:YSGG) at room temperature is described. We obtained 1.643 micrometers laser action from a 1 cm long 0.7% Er (3% Yb, 1% Cr):YSGG crystal with a 20 mJ pump threshold and an 8% slope efficiency utilizing an Er:glass 1.532 (mu) pump laser.