Finally I'll add, if used indoors, then be aware the white LEDs and florescent lights emit in spectral bands and often flicker at 120Hz. You might want to choose a laser color that is different from their peak wavelengths.

As others have stated, modulating (psudo random pulsing of the laser) will also aid in detection. With modulation and the appropriate signal processing you won't need an optical filter unless the red component of the ambient light is so bright that it approaches saturation (and the modulation is lost).

You will see some photodiodes with specific response ranges. But they are limited to 10 - 100 MHz ranges so I am guessing they do not have less than a few hundreds of nanoseconds response time.

LEDs also work as photo diodes - just not characterized as such on the datasheet. An LED with its spectral peak close to that of your RED laser will naturally ignore other broad spectrum light sources, and if the LED lens is RED (not clear) then it has a built in optical filter. Finally, the LED viewing angle (field of view as a photodiode) can be reduced to match that of the maximum angle of incidence of the laser.

While I did find a little information in searching your site I am still unsure what to use in my application. I want to detect the (red) laser light hitting a screen or target. My questing is what is a good device to use, I read that photo diode is faster than a photo transistor. Can any one give me any part numbers to try?

The title is an old saying, one of many inspired by the railway. Other's include 'On the Right Track' and 'Full Steam Ahead'.

To avoid confusing the detection of the laser with sunlight, or some other light source, the laser needs to be modulated. This needs to be done in such a way that it is easy to discriminate the laser signal from other light sources.

600nm - 680nm filter on photodiode(or phototransistor or thermistor) what you need I suspect. However, they are neither cheap nor as fast as you need it to be I guess. Thats because of the filter of course. They are in limited production usually, I remember that we had a quote for 10 photodiode with 880 nm filter from heimann 35€ for each.

The Megamix was added into the London re-write in 1992, and was added to the German production in 2003. It is an assortment of verses from 'Light at the End of the Tunnel' with lines/verses from other popular songs added in between.

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Simple hand-held laser's can be modulated at about 5kHz, which is well away from mains-powered light modulation (50, 60, 100 or 120Hz), and Infrared remote control (36kHz or higher). Depending on your level of skill, you might build the filter using 'pure electronics', or you might use a small microcontroller.

Light at the End of the Tunnel is the gospel-style finale number from the musical Starlight Express. The company (all railway locomotives and cars) perform the number as a glorification to Steam. The solo lines are taken by Poppa, an old Steam Locomotive, (and Belle the Sleeping Car before she was cut).

And you are right, most of the photodiodes responds to unwanted lights unless they have filter on. However, you can always specialize your application to satisfy your needs such as adding some modulation, arranging the receipt sensitivity and gain etc..

I'd recommend starting with a visible light phototransistor. They are easy to use as detectors, and are cheap, i.e. under $1. (e.g. Vishay TEPT4400). It is over 90% sensitive at about 630nm. These have a wide enough range of wavelengths that they will still pick up infrared light, so use an optical filter, to reduce the intensity of other light sources too.

Application Simple laser target, when the training pistol laser hits the target I need a fast detection. I will experiment with the final output later in this project, to start with I might just turn on a light. I also have realized that other indoor lighting may need to be filtered, I have knowledge of filters, I will later research this.

Almost all photodiodes and phototransistors are fast enough by a factor of 100x, or more. So, as Scott Seidman says, fast detection is not likely an issue.

As the original material was written for two characters as a company to sing, it had to be altered dramatically when one of those characters was deleted. When Belle was cut, several different productions dealt with the loss differently. The London show had Poppa sing the lines she sang in addition to his, and the company took the lines she sang in conversation. In early Bochum, the coaches took all of Belle's lines, and the revised version likened to the London re-write.