If you're using a laser + receiver then you want to blink the laser at 38Khz and use three-pin IR receiver module to detect that signal. It's the type of IR receiver that would be used in TV's, etc. with a remote control, but you want a specific subtype that will allow a continuous 38KHz signal. Vishay describes their modules as "fixed gain" in their product matrix
. They are really quite simple to use; when the receiver sees the light signal it sets its output pin voltage low and when no signal is present it sets its output pin high.
So on your receiver you need to have a row of X many receivers (~9 or so) to cover the physical distance you want and a way to invert the signal to turn a LED on/off when the laser beam is shining on that corresponding receiver. I believe this is the type of method that is used by the type of laser receiver used in your picture.
On the laser end you need to blink that laser at 38Khz and this can be done with an Arduino or more cheaply with just a 555 timer
. Any cheap pen laser will do that without any issue and give you multiple tens of meters of range. A red laser is preferred as that is closest to IR frequency. In your case you need a wide, flat beam and you can find laser pointer modules that will put out a line (I'm sure you've used non-spinning laser levels that cast lines on walls, etc.), but I can't comment on how the reception distance will change in that respect. If the laser line is visible to you then it will be plenty visible to the receiver.