Been working with working with my opto fork using a LDR but i am finding room light light levels i have to adjust the circuit ...
I am going to swap with a light transistor type Sensor ,i have one handy but reading about most transistors and leds can do the same thing when exposed to light i have been experimenting .
I know most opto forks are I R type so this fixes the room light problem but again depends on what you have handy and if you want to make your own ...Experimenting i am finding the clear type LEDs seem to work as well as a light transistor.
Trying a high brightness white with a UV light seems to work very well ...
i tried a luxeon and it works as well on white light ,i think these things are frequency sensitive so you would have to see what works with the light frequency or its band width your trying .
Good to get 2 different things out of the same component !