To determine how much light the OBB KiloArc™ delivers in a specific wavelength region for a given lamp refer to the following spectral output curves for the xenon and mercury-xenon arc lamps. These curves provide an estimation of the percentage of the total optical output power for a given wavelength range of the emitted light from the lamp.
The answer is an astounding 500 mW! Here is how we get that answer as well as a cautionary note about this number.
Calculation: The total power of the 1,000 watt xenon lamp is 100 watts broadband (100,000 mW). Referring to the Band Pass Intensity Chart, and graph, for the xenon lamp indicates that at 400 nm there is approximately 5% of the total lamp output in a 50nm wide band. Therefore in a 5 nm bandwidth at 400 nm there will be approximately 0.5% (1/10th of 50 nm) of the total lamp output. This corresponds to 500 mW.
Caution about available energy: Remember that not all of this light may be available to you for your application. In the first place the KiloArc™ is so powerful that we would recommend using an IR heat filter to prevent damage to secondary optical elements. Although this primarily cuts out the IR there will be some loss at other wavelengths through the water jacketed, water filled, IR filter.
Filter for wavelength selection: If you wanted to use a 5 nm bandpass filter for wavelength selection, then there will also be losses through the filter combinations you would use to filter out the unwanted wavelengths without photo-damaging your filters, as well as coupling losses for any optics you incorporate. Therefore you will end up with less than 500 mW, but you will still have a severely intense beam of light.
Monochromator for wavelength selection: If you are going to use a monochromator to filter and select the 5 nm output at 400 nm, then there are a number of factors to consider before determining exactly how much light will be available through the monochromator. Specifically the slit size required for a 5 nm bandpass, the grating efficiency curve for the grating used, the f/# matching of the monochromator, and the throughput loss of the monochromator coupling. OBB happens to provide a tunable KiloArc™ illuminator that consists of the KiloArc™ lamp housing coupled to a 200 mm focal length monochromator. When using the 1,000 watt xenon lamp a considerable amount of light in the original 8 mm focused spot doesn't even get through the narrow 1.25 mm slits required to obtain a 5 nm bandpass with a standard 1,200 l/mm grating. Firstly we have to remember that the 8 mm spot is actually the FWHM of the total light focused. This means that approximately half of the total power is outside an 8 mm diameter. So, less than 5% of the total focused light gets into the monochromators narrow 1.25 mm slit in the first place. Additionally, depending on the grating used, its wavelength angle, its efficiency curve as well as the coupling loses of the monochromator you will have a total throughput for the monochromator of roughly 30%. This results in about 10 mw of energy delivered through the monochromator at 400 nm in a 5 nm bandpass. This number is in good agreement with our empirical results for the Tunable KiloArc™. Refer to the Tunable KiloArc™ web page for the corresponding output curve. Also remember that other monochromators, and certainly different gratings will have affects that will have an impact of the total throughput.
