4. PHOTON SOURCES AND THE NUMBERPHASE UNCERTAINTY A pulsed laser source operating at 693 nm emits pulses of energy 1 m. a.) Calculate the quantum uncertainty in the phase of the laser light. b.) If the pulses are attenuated to an energy of 1 pg) what is the quantum uncertainty in the phase of the light? c.) Discuss the suitability ofthe light sources above for an optical communications link yis-ayis the numberphase uncertainty relationship, and compare with the case where the laser source is replaced by a single photon source