Striving for the fundamental and practical signal to noise limit

We present methods to enhance the response and reduce the noise in a broad class of ultrafast laser sensors, including but not limited to gyroscopes, accelerators, field sensors, and displacements.. Sensitivity enhancement through “exceptional points” was inspired by quantum mechanics. It is shown that this enhancement comes at the cost of a faster increasing noise. However, we demonstrate enhancement without noise increase in mode-locked lasers where two uncoupled pulses circulate at the same group velocity, without any coupling. Such sensors having reached the classical noise limit, quantum mechanical squeezing methods to further increase the signal to noise will be discussed.