构造了三类压缩算符，将其中任何一类作用于相干态，均可得到具有任意压缩度的理想压缩态.熟知的压缩算符是 其中一类的特殊情况.三类算符互不等价，即不能通过线性正则变换互相转化.

The squeeze operators of three classes are presented. The ideal squeezed states with arbitrary degree of squeezing can be obtained by acting any one of them on coherent states. The familiar squeezed operator is a special case of the three classes. The three classes are not equivalent to one another，namely，they cannot be transformed into one another by linear canonical transformations