The calculation of the optical power density of the illumination on the DMD in the different wavelength bands uses the total measured optical power on the DMD, percent illumination overfill, area of the active array, and the ratio of the spectrum in the wavelength band of interest to the total spectral optical power.

• ILL_UV7 = [OP_UV-RATIO × Q_INCIDENT] × 1000 (mW/W) ÷ A_ILL (mW/cm²)
• ILL_UV6 = [OP_VIS-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• ILL_UV5 = [OP_VIS-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• ILL_UV4 = [OP_VIS-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• ILL_UV3 = [OP_VIS-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• ILL_UV2 = [OP_IR-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• ILL_UV1 = [OP_IR-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• ILL_UV = [OP_IR-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• ILL_VIS = [OP_BLU1-RATIO × Q_INCIDENT] ÷ A_ILL (W/cm²)
• A_ILL = A_ARRAY ÷ (1 – OV_ILL) (cm²)

where:

• ILL_UV7 = UV7 illumination power density on the DMD (mW/cm²)
• ILL_UV6 = UV6 illumination power density on the DMD (W/cm²)
• ILL_UV5 = UV5 illumination power density on the DMD (W/cm²)
• ILL_UV4 = UV4 illumination power density on the DMD (W/cm²)
• ILL_UV3 = UV3 illumination power density on the DMD (W/cm²)
• ILL_UV2 = UV2 illumination power density on the DMD (W/cm²)
• ILL_UV1 = UV1 illumination power density on the DMD (W/cm²)
• ILL_UV = UV illumination power density on the DMD (W/cm²)
• ILL_VIS = VIS illumination power density on the DMD (W/cm²)
• A_ILL = illumination area on the DMD (cm²)
• Q_INCIDENT = total incident optical power on DMD (W) (measured)
• A_ARRAY = area of the array (cm²) (data sheet)
• OV_ILL = percent of total illumination on the DMD outside the array (%) (optical model)
• OP_UV7-RATIO = ratio of the optical power for wavelengths < 341nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_UV6-RATIO = ratio of the optical power for wavelengths ≥ 343nm and < 345nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_UV5-RATIO = ratio of the optical power for wavelengths ≥ 345nm and < 355nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_UV4-RATIO = ratio of the optical power for wavelengths ≥ 355nm and < 365nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_UV3-RATIO = ratio of the optical power for wavelengths ≥ 365nm and < 385nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_UV2-RATIO = ratio of the optical power for wavelengths ≥ 385nm and < 400nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_UV1-RATIO = ratio of the optical power for wavelengths ≥ 400nm and < 410nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_UV-RATIO = ratio of the optical power for wavelengths ≥ 365nm and < 410nm to the total optical power in the illumination spectrum (spectral measurement)
• OP_VIS-RATIO = ratio of the optical power for wavelengths ≥ 410nm and < 800nm to the total optical power in the illumination spectrum (spectral measurement)

The illumination area varies and depends on the illumination overfill. The total illumination area on the DMD is the array area and overfill area around the array. The optical model is used to determine the percent of the total illumination on the DMD that is outside the array (OV_ILL) and the percent of the total illumination that is on the active array. From these values, the illumination area (A_ILL) is calculated. The illumination is assumed to be uniform across the entire array.

From the measured illumination spectrum, the ratio of the optical power in the wavelength bands of interest to the total optical power is calculated.

Sample Calculation—Illumination 365nm – 410nm