Hello. I've started building up a system in which two laser beams may be measured by using two OPT301M. These beams are provided from an unique laser diode, whose beam pass through a prism which divides it in two beams with inversely proportional intensities, according to the optical rotation. As I vary the laser's current, without move physically either the laser or the prism, the response from the two OPT301M are differents, seeming actually nonlinear. For instance, if I start increasing the laser current, I get initially from the sensor A 1,5V and from sensor B 0,5V. Increasing more the laser current, sensor A reaches 2V and sensor B 1,75V. Keeping increasing the current, sensor A reaches 2,5V and sensor B 3V. Then finally, keeping increasing, sensor A reaches 4V and sensor B 3,5V. So, one time, sensor A has bigger output signal than sensor B. Another time, sensor B has bigger output signal. I hope I didn't have done a big mess here.
How reliable can be a system using more than one single OPT301M? What could cause this nonlinear behaviour in the output's response?