Diode-pumped Nd3 Research Articles

Efficient multiwavelength operation of a diode-pumped Nd:YAlO3 laser at 1064, 1072 and 1079 nm

Polarization investigation of the emission spectrum of Nd ions at the 4F3/2 → 4I11/2 transition in the b-cut Nd3+:YAlO3 crystal showed that this gain medium is promising for multiwavelength laser operation. A diode-pumped continuous-wave Nd3+:YAlO3 laser with an intracavity retardation plate and a dichroic output coupler demonstrated dual-wavelengths operation at 1064.5 & 1072.6 nm and 1072.6 & 1079.5 nm, as well as triple-wavelengths lasing at 1064.5 & 1072.6 &1079.5 nm. Low intra-cavity losses in the retardation plate allowed achieving a high laser efficiency close to that of a single-wavelength laser. The output power of the triple-wavelength laser reached 1.75 W under a pump power of 6.7 W with a slope conversion efficiency of 32.3 %.

Compact self-illuminated image upconversion system based on intracavity second-harmonic generation.

We present an image upconversion system based on intracavity Type II second-harmonic generation to create an image in the visible spectrum of a target illuminated by an infrared laser. The system has the novelty of being self-illuminated. It uses some fractional leaking power of the infrared laser to illuminate a target located in the object focal plane of the system, and to couple back a created infrared target image to an intracavity nonlinear crystal, where it mixes with the cavity laser beam to obtain a second-harmonic image, visible with a silicon CCD camera. For a proof of concept, we have built a system based on a diode-pumped Nd3+:YVO4 continuous-wave (cw) laser and an intracavity KTP crystal to upconvert 1342nm target images to 671nm. The upconverted cw power allowed us to capture real-time video in a standard nonintensified CCD camera, with 2.5W of a diode pump.

New method of Q-switching with mode locking in solid-state lasers

A new method is proposed for performing a Q-switched laser operation with mode locking by using a spherical mirror (SM) and one traveling wave acousto-optic modulator (AOM), the SMAOM method. The temporal, spectral, and energy output characteristics of a diode-pumped Nd3+:YAG laser with SMAOM, along with the new results on obtaining powerful ultraviolet and mid-IR radiation based on the pumping of nonlinear crystals by such a laser, are presented.

Laser characteristics of Nd3+-doped calcium barium niobate ferroelectric crystal at 1.06 and 1.34 μm.

We report on diode-pumped Nd3+-doped calcium barium niobate ferroelectric crystal (Nd:CBN-28) lasers at 1.06 and 1.34μm. The maximum output power of the 1.06μm laser reaches 0.69W in the continuous-wave regime, which is believed to be the highest output power with Nd:CBN-28 crystal to date. Using a chopper to modulate the pump, the highest output power further improves to 0.77W. Passively Q-switched laser operation at 1.06μm, using a Cr:YAG saturable absorber, is realized with a maximum average output power of 89mW, a pulse width of 220ns, and a pulse energy 10.8μJ. A quasi-continuous-wave laser at 1.34μm with a chopper is also demonstrated with maximum output power of 56mW. The scaled output power in the fundamental wave should be favorable for the investigation on broadband nonlinear self-frequency conversion into visible.

Red Eu,Yb:KY(WO4)2 laser at ~702 nm

In this letter, laser operation is demonstrated with a Eu,Yb: KY(WO4)2 crystal on the 5D0 → 7F4 transition of the Eu3+ ion. When pumping into the 7F1 → 5D1 absorption band by a diode-pumped Nd3+:KGd(WO4)2/KTP laser power-scaled at 533.6 nm up to a watt-level, we achieved 2.5 mW of the continuous wave (CW) red output at ~702.1 nm. At quasi-CW pumping with a duty cycle of 10%, the peak power of the ms-long pulses arrived at ~19 mW, corresponding to a green-to-red conversion efficiency of 0.8%.

Single- and multi-wavelength laser operation of a diode-pumped ND:GGG single crystal around 1.33 µm

We report on the first continuous-wave laser operation of a diode-pumped Nd:GGG single crystal at several emission wavelengths in the 1.33µm spectral domain. Multi-wavelength laser operation at 1324, 1331 and 1337nm with a maximum laser output power of 1.83W and a laser slope efficiency of 28.9% for an output coupler transmission of 2.2% is obtained in the free-running regime. By inserting and tilting a 0.1-mm BK7 glass etalon to modulate the losses inside the laser cavity, single wavelength lasing at 1324nm and 1347nm are also achieved with maximum output powers of about 0.77W and 0.41W as well as laser slope efficiencies of 15.2% and 12.6%, respectively. Further increasing the pump power, based on the position of the etalon leading to the single laser wavelength operation at 1347nm, stable dual-wavelength laser operation is demonstrated at 1337 and 1347nm with a maximum output power of 0.61W.

Studies on simultaneous dual wavelength operation at 912.2nm and 914nm from dual gain diode-pumped Nd3+ doped vanadate laser

Abstract A laser is constructed comprising of Nd 3+ doped yttrium vanadate (Nd:YVO 4 ) and gadolinium vanadate (Nd:GdVO 4 ) in order to obtain simultaneous dual wavelength operation at 914 nm and 912 nm emitted by the respective crystals under 4 F 3/2 → 4 I 9/2 laser transitions. The performance of the laser is studied experimentally and analyzed using laser rate equation model incorporating the cross saturation terms. The simulated trend of variation of output power at 912 and 914 nm as a function of pump power agrees reasonably well with the experimental data and confirms that the saturation of gain at Nd:GdVO 4 crystal by the 914 nm is much stronger than the saturation of gain at Nd:YVO 4 crystal by the 912 nm. It has been found that to obtain simultaneous dual wavelength operation the relative gain at the Nd:GdVO 4 crystal should be considerably higher than that at the Nd:YVO 4 crystal. At a pump power of 29.7 W and 22.6 W applied to Nd:GdVO 4 and Nd:YVO 4 crystals respectively, 1.3 W of output power at 912.2 nm and 1.7 W of output power at 914 nm was obtained simultaneously. The frequency difference of the two wavelengths is 0.73 THz and the state of polarization of the two wavelengths can be easily varied by changing the relative orientation of the c -axes of the crystals.

A diode-pumped Nd3+-doped gadolinium gallium garnet quasi-three-level laser at 933 nm

We report for the first time a Nd3+-doped gadolinium gallium garnet (Nd:GGG) laser operating on a quasi-three-level laser at 933 nm, based on the 4F3/2–4I9/2 transition. Continuous wave 691 mW output power at 933 nm is obtained under 10.2 W of incident pump power. Moreover, intracavity second-harmonic generation has also been achieved with a blue power of 89 mW by using a LiB3O5 (LBO) nonlinear crystal.

Diode-pumped Q-switched Nd3+ : YAG laser operating in a wide temperature range without thermal stabilisation of pump diodes

A model sample of a compact low-power-consumption Nd3+ : YAG laser emitting 20-mJ pulses with a pulse repetition rate up to 20 Hz (in cyclic duty) at a wavelength of 1064 nm is developed and studied. The laser is designed for operating at external temperatures from –40 to +50 °C. This was achieved by using quasi-end diode pumping without thermal stabilisation of pump diodes.

Remote sensing of Arctic Fjords by Raman lidar: Heat transfer screening by layer of glacier’s relict water

West Spitsbergen fjords have been probed (on shipboard) by a compact Raman lidar (Wave Research Center, Prokhorov General Physics Institute, Russian Academy of Sciences), based on a pulsed diode-pumped Nd3+:YVO4 laser with frequency doubling, in August, 2011. The evolution of lidar signal spectra (Raman, fluorescence, and elastic scattering) when approaching the Paulabreen glacier of the Rinders Fjord has been measured. A new phenomenon was discovered: the formation of an immiscible layer of relict thaw water from the glacier on the sea surface. An increase in the layer thickness (to 5–10 cm near the glacier) was accompanied by a decrease in the layer temperature (which was determined by measuring the distortion of the OH Raman band) and the content of phytoplankton and dissolved organic matter to zero, with a simultaneous increase in the Rayleigh scattering amplitude and a change in the surface color from blue to gray. Smoothing of the rippled sea surface (covered by relict water) at the border of the wake trace (which it rolled down from) was observed for the first time, as far as we know. The mechanism of the formation of a supercooled (t ⩽ 0°C) layer and screening the heat diffusion, which reduces the contribution of the relatively warm sea water (≈3°C) to the thermal balance of Arctic and global climate, is discussed.

Efficient intracavity second-harmonic generation at 930 nm in a BiB3O6 crystal

It is reported that efficient continuous-wave (CW) blue laser generation at 465 nm in a BiB3O6 (BiBO) crystal at type-I phase matching direction performed with a diode-pumped Nd3+:YAlO3 (Nd:YAP) laser. With incident pump power of 18.4 W, output power of 823 mW at 465 nm has been obtained using a 10 mm-long BiBO crystal. At the output power level of 823 mW, the output stability is better than 2.3%.

Simulation of the passively mode-locked laser with a SESAM

By solving the Haus master equation through split step Fourier transform method, several programs which can simulate the soliton mode-locked dynamic processes of the passively mode-locked solid laser with a semiconductor saturable absorber mirror (SESAM) are established, based on a MATLAB environment. The pulse evolution equations are solved numerically. Sample calculations for a diode-pumped Nd3+:YVO4 (0.5% doped) laser with a SESAM are presented to demonstrate the use of the simulation programs and the related formulas. Several theoretical results such as the pulse width, the peak power and the average output power are obtained with a given cavity structure, which are in good agreement with the reported experimental results.

Diode-pumped continuous-wave Nd3+:YAlO3 intracavity-doubled red laser

It is reported that efficient continuous-wave (CW) red laser generation at 670 nm in a LBO crystal at type-I phase matching direction performed with a diode-pumped Nd3+:YAlO3 (Nd:YAP) laser. With incident pump power of 15.6 W, output power of 273 mW at 670 nm has been obtained using a 10 mm-long LBO crystal. At the output power level of 273 mW, the output stability is better than 3.7%.

Diode-pumped Nd:YCOB self-frequency-doubling red laser at 666 nm

It is reported that efficient continuous-wave (CW) self-frequency-doubling red laser at 666 nm performed with a diode-pumped Nd3+:YCa4O(BO3)3 (Nd:YCOB) laser. With a diode pump power of 14.3 W, TEM00 mode red laser at 666 nm of 570 mW is obtained. At the output power level of 570 mW, the output stability is better than 3.5%. The beam quality M2 value is about 1.25. To the best of our knowledge, this is the highest power laser at 666 nm generated by self-frequency doubling of a diode pumped Nd:YCOB laser.

Diode-pumped Nd:YCOB self-frequency-doubling green laser at 530 nm

It is reported that efficient continuous-wave (CW) self-frequency-doubling green laser at 530 nm performed with a diode-pumped Nd3+:YCa4O(BO3)3 (Nd:YCOB) laser. With a diode pump power of 14.3 W, TEM00 mode green laser at 530 nm of 1.07 W is obtained. At the output power level of 1.07 mW, the output stability is better than 5%. The beam quality M2 value is about 1.37. To the best of our knowledge, this is the highest power laser at 530 nm generated by self-frequency doubling of a diode pumped Nd:YCOB laser.

Diode-pumped Nd:YCOB self-frequency-doubling blue laser at 468 nm

We report a continuous-wave (CW) self-frequency-doubling blue laser at 468 nm by a diodepumped Nd3+:YCa4O(BO3)3 (Nd:YCOB) laser. With 14.3 W of diode pump power, a maximum output power of 211 mW in the blue spectral range at 468 nm has been achieved. The beam quality M2 values were equal to 1.16 and 1.23 in X and Y directions, respectively. The output power stability over 30 min is better than 5%. To the best of our knowledge, this is the highest power laser at 468 nm generated by self-frequency doubling of a diode pumped Nd:YCOB laser.

Tunable continuous-wave laser at quasi-three-level with a disordered Nd:LGS crystal

A diode-pumped tunable CW Nd(3+):LGS laser at quasi-three-level has been demonstrated. The output power up to 403 mW at the central wavelength of 904 nm was obtained, corresponding to a slope efficiency of 29.7%. Taking advantage of the broad emission spectrum of the disordered crystal Nd:LGS, we tuned the laser wavelength within the spectral range of 899.8 to 906.6 nm with an etalon inserted into the V-type cavity. To the best of our knowledge, it is the first time to obtain a tunable laser based on the (4)F(3/2)-(4)I(9/2) transition of Nd(3+)-doped crystals.

Diode-pumped CW Nd3+:YAlO3 laser at 1339 nm

A diode-pumped Nd3+:YAlO3 (Nd:YAP) laser emitting at 1339 nm is described. At the incident pump power of 17.8 W, as high as 3.4 W of continuous-wave (CW) output power at 1339 nm is achieved. The slope efficiency with respect to the incident pump power was 23.6%. The output power stability over 60 min is better than 3.5%. The laser beam quality M2 factor is 1.33.

Diode-pumped Nd3+:YAl3(BO3)4 laser at 1338 nm

A high-power diode -pumped Nd3+:YAl3(BO3)4 (Nd:YAB) laser emitting at 1338 nm is described. At the incident pump power of 9.8 W, as high as 734 mW of continuous-wave (CW) output power at 1338 nm is achieved. The slope efficiency with respect to the incident pump power was 9.0%. To the best of our knowledge, this is the first demonstration of such a laser system. The output power stability over 60 min is better than 2.6%. The laser beam quality M 2 factor is 1.21.

Quasi-three level laser based on diode-pumped Nd3+:YAlO3 crystal

We describe the output performances of the 930 nm 4 F 3/2 → 4 I 9/2 transition in Nd3+:YAlO3 (Nd:YAP) under in-band pumping with diode laser at the 803 nm wavelength. An end-pumped Nd:YAP crystal yielded 1.13 W of continuous-wave (CW) output power for 17.8 W of incident pump power. Moreover, intracavity second-harmonic generation has also been achieved with a power of 172 mW at 465 nm by using a LiB3O5 (LBO) nonlinear crystal. The blue beam quality factor M 2 was less than 1.3. The blue power stability was less 3% in 60 min.