Anand,

When the duty cycle is low, IREDs can withstand very high currents. So, you can reduce the size of the current limiting resistor and reduce the duty cycle.

A few years back I designed an IR transmitter in a CF card form factor for use with a PDA. I don't recall which IRED it used (Bruce sold them.) but IIRC I used a 10-ohm resistor and a transistor to drive it. With the 3V supply, I was amazed to find that each one (We did 100% testing.) had 100 ± a foot or two range. Of course, it may have been that the TV used as a target had an extra-sensitive receiver.

I assume you want to use this outdoors where sunlight will be a factor. Choosing a receiver with a narrow bandwidth will help.