A measurement system for analyzing an RF signal, comprising - a sensing medium , including at least one constituent - being pumpable to an initial energy state, and - being excitable from the initial energy state to a higher energy state by exposure to an electric and/or magnetic field; - an optical pump configured to pump the at least one constituent of the sensing medium to the initial energy state; - an antenna configured to expose the sensing medium to an electromagnetic field of the RF signal in order to excite it; wherein light emanating from the pumped sensing medium has a spatial distribution, which depends on the frequency of the RF signal; the measurement system further comprising: - an optical processor comprising a trained diffractive deep neural network being an artificial neural network, ANN , that comprises a number of diffractive layers being arranged in series for traversal by the light emanating from the pumped medium , and that is configured to manipulate the spatial distribution of the light such as to apply a linear transformation to the light emanating from the pumped sensing medium , wherein the ANN is trained based on discrepancies between pairs of output light patterns and desired light patterns; and - an optical detector configured to detect an optical property of the transformed light. - a sensing medium , including at least one constituent - being pumpable to an initial energy state, and - being excitable from the initial energy state to a higher energy state by exposure to an electric and/or magnetic field; - being pumpable to an initial energy state, and - being excitable from the initial energy state to a higher energy state by exposure to an electric and/or magnetic field; - an optical pump configured to pump the at least one constituent of the sensing medium to the initial energy state; - an antenna configured to expose the sensing medium to an electromagnetic field of the RF signal in order to excite it; wherein light emanating from the pumped sensing medium has a spatial distribution, which depends on the frequency of the RF signal; the measurement system further comprising: - an optical processor comprising a trained diffractive deep neural network being an artificial neural network, ANN , that comprises a number of diffractive layers being arranged in series for traversal by the light emanating from the pumped medium , and that is configured to manipulate the spatial distribution of the light such as to apply a linear transformation to the light emanating from the pumped sensing medium , wherein the ANN is trained based on discrepancies between pairs of output light patterns and desired light patterns; and - an optical detector configured to detect an optical property of the transformed light. - an optical processor comprising a trained diffractive deep neural network being an artificial neural network, ANN , that comprises a number of diffractive layers being arranged in series for traversal by the light emanating from the pumped medium , and that is configured to manipulate the spatial distribution of the light such as to apply a linear transformation to the light emanating from the pumped sensing medium , wherein the ANN is trained based on discrepancies between pairs of output light patterns and desired light patterns; and - an optical detector configured to detect an optical property of the transformed light. <EOS>