Any source of infrared, appropriately spaced, will work just fine. At the DIY blog Sprite's Mods they were sick of trying to position their sensor bar with their projector setup.

The infrared sources located in the sensor bar emit lights that can't be seen by the naked eye, but are nevertheless plainly visible by the Wii remote, whose tip features a very basic camera that ...

Does wii u need a sensor bar online, TSV Wired Infrared Sensor Bar Fit for Nintendo Wii Wii U Console Wired IR Ray Motion Receiver Sensor Bar with Stand online $43.00 SKU: 6881449 Colour ...

If you’re not familiar, the Wii remotes have an infrared camera in the tip that sense two IR LEDs in the sensor bar that resides above or below your television.

The front of the Wireless Sensor Bar includes a pair of IR LEDs at either end, a red power-on indicator light, and a red button for turning it on and off. The bottom has a swath of double-sided ...

It turns out the "sensor" bar doesn't actually sense at all, it just sends out a pair of IR beams which can then be triangulated by the Wiimote.

"The Wireless Sensor Bar™ can be used with any Wireless / IR control system that uses anchored IR points, such as the Nintendo Wii Remotes ("Wiimotes"). ~ Uses Wii Standard 3-8 foot ideal range ...

The IR sensor array, which on the palm-sized vehicle consisted of just a handful of components, evolved into a PCB-backed bar nearly 0.5 meters wide. Potentiometer tuning was a fiddly affair, but ...

Maybe they just thought sensor bar would make more sense to people than IR transmitter?<BR><BR>Well, this should at least be a boon to people who use projectors, as it'll be likely that 3rd party ...

Still, "sensor bar" is easier to understand than "IR-emitting diode bar." The Wii's sensor bar takes power from the Wii itself, running a long, thin cord from the Wii to the bar.