another embodiment is shown in fig4 in this arrangement the beam splitters 40 can be uncoated substrates which are less expensive than coated substrates the uncoated substrate will reflect about 10 and transmit about 90 of the incident light again the pmt 32 gets the strongest signal and the pmt 34 gets the weakest signal with the pmts 38 getting increasingly weaker signals as one moves from the pmt 32 to the pmt 34 the designs illustrated in fig3 and 4 may be limited by the damage threshold of the pmt 32 which sees the larger share of the signal there are several ways to deal with the potential damage problem first of all one could modulate the illumination power by modulating the source of light directly or using an external modulator e g for diode laser or led source alternatively the emitted fluorescent light can be modulated to reduce the amount of light going to pmt 32 while leaving the full signal on the pmt 34 this approach would protect both the cathode and dynodes of the pmt 32 alternatively the pmt bias voltage can be modulated for one or more electrodes which will protect dynodes but not the photocathode both the hybrid counting integrating system and the cascaded detector system described above extend signal dynamic range by allowing photon counting at the low end of the dynamic range and extended up to the maximum light load the detector can handle both approaches allow covering dynamic ranges that are limited by the photon counting detection limit at the lower end and by the destruction threshold of the pmt at the high end dynamic ranges well in excess of 10 4 and more are achievable with the designs of this invention it is intended that all modifications and.