How about 10 or more IR leds driven hard and installed at the far end of a long non reflective tube - I assume the non reflective tube will only emit a narrow beam ?
If you go with a LDR, you will need a whole lot of additional electronics (noise filtering, amplifier etc) just to distinguish your signal from the ambient IR noise.
or the reflector big enough to not be affected by the occlusion of the laser beam by the size of the LDR.... Simple.
Where, AWOL do you find 38Khz in a laser?
a waste of time as we aren't trying to turn on the target or change it's channel
Remember that even a small 1/4 watt laser
All that need to be done is chop (pulse) the laser and amplify the received signal a little for detection. No REMOTE CONTROL DETECTORS NO 38KHZ... SIMPLE transmitter and simple receiver.