You should get a big chuckle out of this paper by Owen Smith, SUNY Stony Brook, in which he explains that "the longitudinal modes of a laser are those modes that will laze at slightly different frequencies. Any frequency that has a gain high enough to equal or exceed the losses of the lazing cavity can laze." He probably doesn't realize that LASER is an acronym.
Look, you can spell it however you want, but in general, if you had to choose between the two spellings, you should choose the s. Likewise, you can pronounce forte with two syllables when you're not talking about music, but I'm going to laugh at you.
It has appeared as "taze" in mainstream print sources several times over the past few weeks, usually in reference to the "Don't Taze Me, Man" video on YouTube. It also has several slang definitions listed in the Urban Dictionary, for what that's worth.