Detector cards suck.
I had several digital logic probes laying around. It came to me one day that those little infrared detector cards were expensive and nearly worthless. Why not modify a logic probe to detect IR (and other) light and show pulses as well? Beginning with the Global Specialties LP-1 logic probe, I removed the probe point and installed a phototransistor down in the hole where it would get some shading from ambient light. I "backpacked" an LM1458 dual op amp over the A1 chip (I chose the 1458 because of the pinout), connecting the 1458's pins 4 and 8 to A1's 7 and 14 respectively for power. The 1458 is wired as a comparator, small trimmer pot was added on top of the 1458, the outer legs connected to A1 pin 14 and pin 7 and the wiper to the 1458 pin 2. The phototransistor's collector was tied to A1 pin 14 and the emitter tied through a 100K resistor to ground. The emitter was also connected to the 1458 pin 3. The trimpot was adjusted for a solid indication when the probe was brought near an operating IR remote control. The LOW indicator was removed and the "pulse/memory" and "cmos/ttl" switches removed and jumpered for "pulse" and "ttl" operation since I had negated the traditional logic probe function. A hole was drilled over the trimpot for external adjustment and a new label fashioned to replace the old.
[Looking back, the above paragraph is confusing as all heck. This was an old "tip" that I'd put together but not fleshed out, so construction/modification from the above material is not easy. I just did a quick cut-and-paste from the original material to get a quick post here. Unfortunately, this modified probe is currently boxed up in storage somewhere, so I can't open it up for the correct details. But the whole idea is to get you to find a probe with a known schematic and modify it for optical use.]
Anyway, when light is present, the red LED will light. If the light source is pulsing (such as that from a fluorescent light or IR remote control), the yellow "pulse" LED will light. In addition, a connector can be added to the probe, connecting it to the input of the op amp. This way, you can connect an oscilloscope to the probe and see the actual waveform being detected by the phototransistor.