Showing papers by "Norman P. Barnes published in 1999"
TL;DR: In this article, a closed-form model was developed to characterize the spectral and spatial portions of amplified spontaneous emission in a flashlamp-pumped Nd:YAG laser with a threshold of 12 J and a slope efficiency of 0009.
Abstract: Amplified spontaneous emission can seriously degrade the Q-switched performance of a strong four-level transition such as the 1064 /spl mu/m Nd:YAG transition or can even prevent oscillation on a weaker quasi-four-level transition such as the 0946-/spl mu/m Nd:YAG transition To characterize, and thus be able to mitigate, amplified spontaneous emission, a closed-form model is developed By employing a closed-form solution, the differential equations describing both the evolution and decay of the upper laser manifold population density can be solved exactly An advantage of this model is the separation of the spectral and spatial portions of amplified spontaneous emission Gain measurements, as a function of time and pump energy, are compared with the model and good agreement is found With these principles in mind, a flashlamp-pumped Nd:YAG laser was designed to operate at 0936 /spl mu/m At room temperature, a threshold of 12 J and a slope efficiency of 0009 was achieved
83 citations
TL;DR: In this article, the performance and gain results for both Nd:YAG and Nd-GYAG lasers that operate on the 4F3/2 to 4I9/2 transition are reported as a function of temperature.
Abstract: Nd lasers operating on the 4F3/2 to 4I9/2 transition, usually at ∼0.94 µm, can provide a useful source for many applications when they operate efficiently. Both efficiency and energy output are substantially increased by two new approaches: improvement of the basic design and the use of new laser materials, specifically, Nd:GYAG. Laser performance and gain results for both Nd:YAG and Nd:GYAG lasers that operate on the 4F3/2 to 4I9/2 transition are reported as a function of temperature. For the sake of comparison, results for these lasers when they operate on the 4F3/2 to 4I11/2 transition at 1.064 µm are reported as well. In addition, preliminary second-harmonic generation results for this 0.94-µm laser are reported.
24 citations
23 May 1999
TL;DR: In this article, the gain, wavelength tuning and output characteristics of a high energy Cr:LiSAF laser that is being developed for use in an airborne water vapor DIAL system are presented.
Abstract: Summary form only given. The near-IR absorption bands in the 810-830 nm and 930-950 nm range are well suited for remote measurements of water vapor with differential absorption lidar. A diode-pumped Cr:LiSAF laser which can be tuned over these bands has a great potential as a compact and efficient, narrow linewidth source for atmospheric water vapor DIAL. We present the gain, wavelength tuning and output characteristics of a high energy Cr:LiSAF laser that is being developed for use in an airborne water vapor DIAL system. The laser gain module consists of a 5.5% doped 6/spl times/6/spl times/25 mm Cr/sup 3+/:LiSAF slab pumped from two sides by eight 690 nm diode stacks. For obtaining high extraction efficiency and good laser beam quality a total internal reflection approach is used.
3 citations
29 Apr 1999
TL;DR: In this paper, the authors discussed the cross-reststrahlen band phasematching technique for narrow-band three-wave interactions and reported new measurements of GaP regarding FIR absorption, optical damage threshold and optical quality.
Abstract: We discuss the Cross-Reststrahlen band phasematching technique for narrow-band three-wave interactions. In GaP, assuming a maximum practical crystal length of 100 millimeters, the calculations predict that with a source wavelength of 0.965 micrometers, a tuning range of greater than 50 GHz is possible around the perfectly phasematched 3.0 THz center frequency. When GaP is pumped with a source wavelength of 1.000 micrometers, the coherence length is at least 100 mm for a frequency range of greater than 600 GHz around the perfectly phasematched 630 GHz center frequency. High Resistivity GaP is available in cylindrical boules that are larger than 50 millimeters in diameter and 75 millimeters in length. GaP has a bandgap cutoff wavelength in the Visible at 0.55 micrometers and a simple phonon absorption spectrum with a single fundamental absorption at approximately 27 micrometers, which indicates a potential for high transmission in both the NIR and FIR. Any remaining FIR absorption can be attributed to free electron absorption and two phonon absorption processes. In this paper, we report new measurements of GaP regarding FIR absorption, optical damage threshold and optical quality. These measurements indicate that undoped, high-resistivity GaP single crystal can be used to generate THz waves.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
3 citations
TL;DR: In this paper, several typographical errors were made on page 104 in the fourth and sixth equations, and these errors were corrected by correcting the errors in the second and third equations.
Abstract: In the above-named article, several typographical errors were made on page 104 in the fourth and sixth equations. These are corrected here.
3 citations
28 May 1999
TL;DR: In this paper, the authors reported a flashlamp pumped, room temperature, normal mode, Nd:YAG operating at reduced temperatures, /spl ap/248/spl deg/K.
Abstract: Summary form only given. While continuous wave operation of Nd:YAG at 0.946 /spl mu/m has made significant advances, pulsed operation has remained at low energies or operated at reduced temperatures. Reported here are flashlamp pumped, room temperature, normal mode energies approximately 3 times higher than previous reports of a flashlamp pumped, normal mode, Nd:YAG operating at reduced temperatures, /spl ap/248/spl deg/K. Also reported are Q-switched energies approximately 5 times higher than previously reported Q-switched using end pumping. Measured performance data on a new laser material, Nd:GYAG, indicates better 0.946 /spl mu/m operation than obtained with Nd:YAG.
1 citations
28 May 1999
TL;DR: In this paper, the authors studied the possibility of broadening and compositional tuning of the 0.8 /spl mu/m absorption lines and 0.94 and 1.06 /spl µ/m emission lines in Nd doped (Ba/sub x/Sr/sub 1-x/)/sub 5/(PO/sub 4)/sub 3/F, Ba/sub 6/(P/sub 5/V/sub X/O/sub V/sub O/O)/sub 4/F).
Abstract: Summary form only given. We study the possibility of broadening and compositional tuning of the 0.8 /spl mu/m absorption lines and the 0.94 and 1.06 /spl mu/m emission lines in Nd doped (Ba/sub x/Sr/sub 1-x/)/sub 5/(PO/sub 4/)/sub 3/F, (Ca/sub 1-x/Sr/sub x/)/sub 5/(PO/sub 4/)/sub 3/F, Sr/sub 5/(P/sub 1-x/V/sub x/O/sub 4/)/sub 3/F, and Ba/sub 5/(P/sub 1-x/V/sub x/O/sub 4/)/sub 3/F. These crystals have been grown by the Czochralski technique and have good optical quality. The emission wavelengths in the end members are in a fair agreement with our theoretical calculation of the Stark energy levels.