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共焦非稳腔中ps激光的内腔倍频 总被引:2,自引:1,他引:1
考虑倍频晶体相位匹配接收角(Angular acceptance)对倍频转换效率的影响,设计了正支(p支)共焦非稳腔Nd:YAP锁模激光器。平行光通过晶体实现完全相位匹配。以BBO和KTP作为腔内倍频元件,分别获得80.6%和60.2%的高效倍频转换,及几十mJ的绿光输出。同时实验测定其它有关参数。 相似文献
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本文描述我们设计的带抗共振环 (ARR)的对撞脉冲锁模 (CPM )非稳腔Nd :YAP和Nd :YAG激光器 ,该激光腔结合了CPM腔脉宽窄、工作稳定和非稳腔输出能量高的特点 ,是一理想的高功率激光器 同时选择了KTP、BBO和LBO等优良非线性晶体作为腔内倍频元件 ,实现高效倍频转换 获得× 1 0mJ和 5GW /cm2 的高能量和高功率绿光皮秒脉冲输出 ,倍频转换效率高达 ( 50~ 70 ) % 相似文献
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V. N. Belyi N. V. Kondratyuk A. A. Shagov A. G. Mashchenko 《Journal of Applied Spectroscopy》2000,67(2):364-368
Special features of the parameteric amplification of light in a BBO crystal in the pumping field of YAG:Nd laser radiation
(λ=1.064 μm) were investigated in the case in which the wavelength of the amplified signal of light lay within the eye-safe
region of the spectrum and the idle wavelength lay within the region of strong absorption. The correlation between the parametric
gain coefficient and the linear absorption coefficient of the crystal has been revealed.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 2, pp. 263–266, March–April, 2000. 相似文献
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In this paper the effect of the growth temperature fluctuation, for instance, the transient furnace temperature variation due to a short‐term electric power supply interruption on BBO crystal growth was investigated based on the theory of temperature wave transmitting in melt and the boundary layer theory of melt. It was found that the critical width of the temperature pulse to avoid the temperature wave penetrating through the boundary layer and reaching to the growth interface at a constant rotation speed (9∼4 r/min) is 69∼150 s and the corresponding amplitude of the temperature pulse is high more than 60 °C due to the large thickness of the velocity boundary layer of the melt. This result indicates that a small transient temperature fluctuation has no significant effect on the crystal quality, and therefore implies that not only transport processes but interface growth kinetics, a two‐dimensional nucleation growth mode at the interface may also dominate the crystal growth. 相似文献
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β-BaB2O4 (BBO) crystals with well-defined morphology have been grown from Na2O solutions using the top seeded solution growth (TSSG) method. The crystal morphology in relation to its structure and growth conditions has been studied in detail on the basis of crystallography and crystal chemistry. It is found that the morphological characteristics are related to the orientations of structural unit (B3O6)3— anion rings in the crystal. On the other hand, the growth parameters may greatly affect the appearance of faces of the crystal, but the crystals still generally take trigonal in outline and have a diagnostic character of point group 3m. The observed morphology is in disagreement with BFDH and PBC analyses and is explained from the incorporation of the growth units on the faces and facets. Since the incorporation rates of the growth units are different on different faces, the boule habits with well-defined morphology are formed. 相似文献
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D. Perlov S. Livneh P. Czechowicz A. Goldgirsh D. Loiacono 《Crystal Research and Technology》2011,46(7):651-654
Growth of large β‐barium borate (BBO) crystals of high optical quality has been challenging, even 25 years past its discovery. The best results in terms of size and quality have been demonstrated by means of TSSG (Top Seeded Solution Growth). Nevertheless, the maximum available size of nonlinear optical elements lags behind laser industry requirements. Due to increased size and availability, BBO finally started attracting attention for its favorable Q‐switch properties. Yet, two or sometimes three crystals aligned together are still necessary to achieve the lengths often required for these applications. Material quality, in terms of optical perfection and optical absorption, is still questionable in many instances. Limited boule size still dictates relatively high material cost as well. Thorough analysis of the growth behavior of BBO helped us to develop production processes for large boules utilizing TSSG with pulling. High quality nonlinear optical crystal devices and Q‐switches up to 40 mm in the z‐direction have been enabled. We believe that the above size and quality are currently industry leading. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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This paper describes a novel chaotic biogeography-based optimization (CBBO) algorithm for target detection by means of template matching to meet the request of unmanned aerial vehicle (UAV) surveillance. Template matching has been widely applied in movement tracking and other fields and makes excellent performances in visual navigation. Biogeography-based optimization (BBO) algorithm emerges as a new kind of optimization method on the basis of biogeography concept. The idea of migration and mutation strategy of species in BBO contributes to solving optimization problems. Our work adds chaotic searching strategy into BBO and applies CBBO in template matching. By utilizing chaotic strategy, the population ergodicity and global searching ability are improved, thus avoiding local optimal solutions during evolution. Applying the algorithm to resolving template matching problem overcomes the defects of common image matching. Series of experimental results demonstrate the feasibility and effectiveness of our modified approach over other algorithms in solving template matching problems. Our modified BBO algorithm performs better in terms of convergence property and robustness when compared with basic BBO. 相似文献
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