A test and measurement instrument including a time domain channel configured to process a first input signal for analysis in a time domain; a frequency domain channel configured to process a second input signal for analysis in a frequency domain; and an acquisition system coupled to the time domain channel and the frequency domain channel. The reconstruction of the biological tissue image is performed by measuring spectra having a two-dimensional distribution correlated with a biological tissue section, and acquiring a biological tissue image from the two-dimensional measured spectra through utilization of the measured spectra and an classifier. The method also includes filtering the third resultant signal to remove the pump signal and the idler signal and outputting the amplified source optical signal.