length n. 1.长,长度,长短。 2.(时间的)长短,期间。 3.(赛艇的)一艇的长度;一马的长度。 4.程度,范围。 5.【板球】球程;投至适当距离的球。 6.【语言学】音长。 7.一段,一节。 a dress length, a length of cloth 一段料。 a length of pipe [tubing] 一节管子。 The boat won by three lengths. 这只艇以三艇长之差得胜。 a (good) length ball 球程准确的球。 at arm's length 在手臂伸得到的地方,疏远 (keep sb. at arm's length 不与接近,敬而远之)。 at full length 1. 冗长地;充分地,详细地 (give all the facts at full length 提供详细的材料)。 2. 全身平伸地 (lie at full length 挺直身体躺着)。 at great length 冗长地,??唆唆地。 at length 1. 最后,终于,好容易才。 2. 充分地,详细地 (speak at great length 详细讲了好久)。 at some length 相当详尽地。 cannot see beyond the length of one's nose 鼠目寸光。 draw out to a great length 拖得很久,占去很长时间。 fall [measure] all one's length 直挺挺地倒下。 find [get, have, know] the length of sb.'s foot 了解某人的弱点。 go (to) all lengths [any length] = go to great lengths 什么事都做得出;不遗余力。 go (to) the length of (doing) 甚至于,不惜。 go the whole length of it. 彻底干;干到底。 length of (sb.'s) days [life] 某人的寿命。 measure one's (own) length 跌倒在地。 of some length 相当长。 over [through] the length and breadth of 到处,四面八方。 work at arm's length 在不利的条件下工作。
The gain characteristics of edwa have been investigated by solving numerically propagation equations and rate equations at pump wavelength 980nm . the gain characteristics are functions of waveguide length , erbium concentration and pump light power , so the relations between them are analyzed in detail in this paper . the size of edwa is also discussed here , which has some reference value for the following study and the design of waveguide amplifier 通过解析速率方程和传输方程,在波长为980nm泵浦光作为泵浦源的条件下,对掺铒光波导放大器的增益特性进行了分析,由于波导放大器的增益是波导长度、掺铒浓度和泵浦功率的函数,因此本论文对三者与信号增益的关系分别进行了讨论。
In this paper , some investigation and design as following . have been carried out on er - yb codoped phosphate glass waveguide laser first , three primary performance parameters of er - yb waveguide laser pump threshold power ; output power and slope efficiency have been commulated and analysed theoretically based on er ~ ( 3 + ) - yb ~ ( 3 + ) energy configuration ; rate equation of stable state and transmitting equation . the influences of er - yb ions concentration ; enabled waveguide length ; light dot radius of signal light and pump light ; reflectivity of output lens on three above parameters have been researched 首先,从er ~ ( 3 + ) - yb ~ ( 3 + )能级结构出发,结合激光稳态速率方程与传输方程,对铒镱波导激光器的三个主要性能参数:阈值功率、输出功率、斜率效率作了理论计算分析,并研究了铒、镱离子浓度、光波导激活长度、信号光与泵浦光光斑半径比例、输出耦合镜反射率对这三个关键性能参数的影响。