diodelaser 发表于 2007-5-4 20:02:00

连续、准连续（QCW）、脉冲半导体激光器的区别

半导体激光器工作方式有连续、准连续（QCW）、脉冲，这三种工作方式 的半导体激光器有什么区别？特别是QCW与脉冲，内部结构有什么区别，驱动器是一样的吗？

wuyijie 发表于 2007-6-25 12:46:05

我也不明白。希望高手解释一下。

billyexpert 发表于 2007-6-25 13:23:11

主要是根据调Q方式的不同,造成激光的脉冲宽度不同.连续是指连续出光，非脉冲方式. 准连续是由于调Q的开关光速度较慢,造成脉冲宽度比较大,从波形上来说,不够陡.因此准连续实质上也是属于脉冲方式.因此大家可以看见普通打标机也有提到频率是多少KHZ的.而如果是连续的激光器,是没有频率可言的.

billyexpert 发表于 2007-6-25 13:23:19

一般打标机是声光调Q,属于准连续.

[ 本帖最后由 billyexpert 于 2007-6-25 13:24 编辑 ]

wuyijie 发表于 2007-6-26 11:02:57

谢谢！
请问准连续的优势是什么？
为什么需要脉宽大呢？
这样是不是比普通的脉冲的峰值功率小？

linjipeng 发表于 2007-6-27 11:08:50

准连续大多是用连续光泵浦，声光调制提高光的峰值功率，增强激光与物质的相互作用。

billyexpert 发表于 2007-6-27 15:16:27

在打标中起作用的不仅仅是峰值功率,毕竟不是冷加工,热聚集的效果还是很明显的,因此单脉冲能量大一些,脉冲宽度大一些,打标效率也高一些.当然,要是峰值功率特别高,单脉冲能量小一些也可以打标,但是打标出来的效果是不同的,这就有点向冷加工的方向发展了.

fengjiang81 发表于 2007-6-28 08:46:12

而如果是连续的激光器,是没有频率可言的这句话可以理解为连续激光器的频率无穷大吗？

billyexpert 发表于 2007-6-28 09:50:55

不能.不要用到无穷的概念,一旦到了无穷,很多事情就差别很大,甚至是本质的变化.因为连续和脉冲的工作原来和结构都有很大的差异.

newstarce 发表于 2007-6-30 11:28:35

QCW是否是占空比很高，接近100%的脉冲调制呢？

billyexpert 发表于 2007-7-3 15:22:28

可以这么说.

无聊瓜子 发表于 2007-7-11 22:32:17

Quasi-continuous-wave operation

Definition: an operation mode of lasers (e.g. diode bars) where the pump power is switched on for short time intervals in order to limit thermal effects

Quasi-continuous-wave (quasi-cw) operation of a laser means that its pump source is switched on only for certain time intervals, which are short enough to significantly reduce thermal effects, but still so long that the laser process is close to its steady state, i.e., the laser is optically in the state of continuous-wave operation. The duty cycle (percentage of "on" time) may e.g. be a few percent, thus strongly reducing the heating and all the related thermal effects, such as e.g. thermal lensing and damage through overheating. Therefore, quasi-cw operation allows to achieve higher output peak powers at the expense of a lower average power.

Pulsed operation with significantly shorter pumping times is called gain switching.

Quasi-continuous-wave operation is most often used with diode bars and diode stacks. Such devices are sometimes even designed specifically for quasi-cw operation: their cooling arrangement is designed for a lower amount of heat extraction, and the emitters can be more closely packed in order to obtain a higher brightness and beam quality. Compared with ordinary continuous-wave operation, additional lifetime issues can result from quasi-cw operation, related e.g. to higher optical peak intensities or to frequent temperature changes.
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