A device for measuring a phase noise in a signal, comprising: an input port configured to receive an oscillation signal from an oscillator under test; a first photonic signal processing branch circuit configured to process the oscillation signal to produce a first branch output signal; a second photonic signal processing branch circuit configured to process the oscillation signal to produce a second branch output signal, wherein the first and second photonic signal processing branch circuits share a common optical module that includes a shared laser configured to produce continuous wave laser light at first and second wavelengths, a shared optical modulator configured to modulate the laser light at the first and second wavelengths to produce modulated laser light that carries the oscillation signal, a shared optical delay configured to receive the modulated laser light from the shared optical modulator, and a wavelength-selective optical device configured to separate the modulated laser light output by the shared optical delay into a first modulated laser beam at the first wavelength and into a second modulated laser beam at the second wavelength; the first photonic signal processing branch circuit being further configured to process said first modulated laser beam to produce the first branch output signal and the second photonic signal processing branch circuit being further configured to process said second modulated laser beam to produce the second branch output signal; and circuitry configured to receive the first and second branch output signals to measure noise in the received oscillation signal and configured to control the first and second photonic signal processing branch circuits and measurements of the noise in the received oscillation signal. an input port configured to receive an oscillation signal from an oscillator under test; a first photonic signal processing branch circuit configured to process the oscillation signal to produce a first branch output signal; a second photonic signal processing branch circuit configured to process the oscillation signal to produce a second branch output signal, wherein the first and second photonic signal processing branch circuits share a common optical module that includes a shared laser configured to produce continuous wave laser light at first and second wavelengths, a shared optical modulator configured to modulate the laser light at the first and second wavelengths to produce modulated laser light that carries the oscillation signal, a shared optical delay configured to receive the modulated laser light from the shared optical modulator, and a wavelength-selective optical device configured to separate the modulated laser light output by the shared optical delay into a first modulated laser beam at the first wavelength and into a second modulated laser beam at the second wavelength; the first photonic signal processing branch circuit being further configured to process said first modulated laser beam to produce the first branch output signal and the second photonic signal processing branch circuit being further configured to process said second modulated laser beam to produce the second branch output signal; and circuitry configured to receive the first and second branch output signals to measure noise in the received oscillation signal and configured to control the first and second photonic signal processing branch circuits and measurements of the noise in the received oscillation signal.