LASER receivers

im doing a project on lasers .
Can somebody tell me about laser sensors .types and circuit , sensitivity. Sensors which can be used at a distance of 1 to 1.5 km.

Any photo diode, or photo transistor that is sensitive to the wavelength of the laser outputs, look up photo diode or photo transistor detector circuit and you will find plenty of links.

The distance of reception has very little to do with the receiver in this case, the laser source is the important part.

thanx a lot