GE optical ports of the switch cannot use 10GE optical modules. Similarly, 100M optical ports cannot use GE or 10GE optical modules.

Yes for shure you can?t use 10GE optical modules in GE socket!

Yes, its true. Although it would be nice if the optical modules and could work at lower speeds.

Cant of course,  there are many differences between GE and 10 GE besides the bandwidth.

For example, the wavelength, optical power, encapsulation type, receiver sensitivity, extinction ratio,, and son on.

This is of course understandable. From the verge of fantasy - Plug-in module 10/100/1000/10000 and he determines the speed, power radiation wavelength. Besides, if one laser stop working, then the link can be got by 1000. 


PS. Its just my imagination.