Burnout protection for optical sensors

An apparatus for protecting an optical sensor, comprising:

• a fixed filter having a fixed passband for light transmission;
• a programmable filter having a variable passband for light transmission, the programmable filter including at least two quarter wavelength layers, the first quarter wavelength layer including alternating n-type layers and p-type layers of a first material and the second quarter wavelength layer including alternating n-type layers and p-type layers of a second material;
• and
• a controllable voltage source that shifts the passband of the programmable filter from a first state in which the passband of the programmable filter is substantially the same as the passband of the fixed filter and a second state in which the passband of the programmable filter is different than the passband of the fixed filter.