To some extent optical links can be almost completely immune to sunlight!
The signals are modulated on a "carrier frequency" the baseline rate at which the laser is modulated. For TV and appliance remote controls using infrared LEDs the frequency is something like 38 kHz, but for a telemetry signal using a modulated communications laser it could be much, much higher, whereas sunlight will be almost DC or tens of Hz and light is modulated by clouds, plumes from cold gas thrusters, etc.
Even a modulated laser will also be very narrow band, so a narrow-band optical filter on the receiver will further cut out sunlight. It might be 1 nm or even less and still have no problem passing almost all the laser light while cutting Sunlight down by a factor of order 1000; a 1 nm wide bandpass at say 850 nm will have roughly about 1/1000 of the Suns output in it.
An optical receiving telescope will be centered on the position of the rocket and have perhaps a few degree field of view at most. A fast-acting, tiny electromechanical or MEMS mirror will keep the target centered on a small photodiode, and the amount of blue sky or background cloud coincident in this small area will be tiny.
Cubesat with active mirror pointing from this answer to Using what technology one can keep a spacecraft truly non rotating
See also the following, and links therein