What are some LED technology for one dimensional coherent light emission?
It's very difficult to collimate an LED output efficiently, and LED output is not coherent. 

But, many laser diodes naturally emit a pattern like you drew. The reason is that the laser cavity is typically several microns across in the horizontal direction, but only a fraction of a micron tall in the vertical dimension. Due to diffraction, this results in an emitted beam with very large divergence vertically (like 40 degree full-angle) and much less divergence horizontally (10, 15, 20 degrees, maybe). For example, see these specs for a 10 mW laser from ThorLabs:



If a radially symetric output beam is needed, special output optics (like the cylindrical lenses mentioned in other answers) are used to correct for the problem.

So what you might really want is just an IR laser diode with no such corrective optics, or with corrective optics only to collimate the beam horizontally.  

If you search "line-laser IR" you might also find some devices pre-packaged with suitable optics.

One more note, you expressed some concern about 


  high power, which makes them hazardous 


Realize that the eye safety of a laser depends on how much power the laser can deliver to the roughly 1 mm2 aperture of a human eye. A laser emitting in a long line will only deliver a small fraction of it's power to any particular 1 mm2 spot, so the danger is much reduced. Of course, while you're working on the system if you might get your face within a few inches of the laser, or look at it through magnifying optics, you will want to be very cautious to keep the laser off or reduce it's output power at that time.