Burglar circuit use laser or infrared

Hi, I see burglar circuit use laser or infrared a lot of in internet. But i do not know which one will work. I need circuit diagrams in detail: laser or infrared, components.I do not know much about the circuit please help me.

they both will work but achieve completely different things. So you need to work out what you want to do?

laser = trip wire type arrangement for detecting an intrusion
IR = movement detection with large area coverage

A simple google search and you will find circuits / DIY development kits for both types.