type have been demonstrated by many researchers and at least one is commercially available from lynx photonic networks inc fig4 depicts an embodiment with a blocking 4 u00d7 1 matrix tdm optical switch according to the present apparatus in which an optical gate and a phase modulator are omitted in this embodiment of a tdm wdm system four fm frequency modulated lasers 401 402 403 404 of separate wavelengths u03bb 1 u03bb 2 u03bb 3 u03bb 4 are operatively coupled to inputs of a matrix switch 406 the output has the sequence of pulses where wavelengths u03bb 1 u03bb 2 u03bb 3 u03bb 4 occur in separate pulses and where the sequence repeats fig5 depicts an embodiment of the present system in which a single wavelength channel may be switched to four separate output channels 511 512 513 514 in this fashion a single laser 501 may interrogate four times as many hydrophones for example as compared to known systems thus quadrupling the acoustic sensor sampling rate per laser an input of the nonblocking 1 u00d7 4 matrix switch 508 may be operatively coupled to the laser 501 via an optical gate 504 and phase modulator 506 in other embodiments the optical gate 504 and the phase modulator 506 may be omitted if a blocking matrix is used with an fm modulated laser the outputs of.