I'm making a light barrier and working on a "sender" part right now. The main thing I want to achieve is the maximum distance. I'm using Vishay TSSP4038 (see http://www.kynix.com/Parts/2490198/TSSP4038.html) for receiving signal. In the datasheet it's stated that it can work on distances about 30m. I can't get even close. With 350mA (1W) LED it's about 3m max (outdoors).
Here is my current schematic:
T1 is NPN transistor. Q2 is N-channel mosfet. LED power schematic is taken from this instructable.