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https://www.ias.ac.in/article/fulltext/jbsc/038/01/0009-0012

Firefly light; pulse amplitude modulation; pulse width modulation

Continuous light could be produced from the firefly by making it inhale vapours of ethyl acetate. Here we perform such a control experiment on the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae), and analyse the light in the microsecond time scale. The amplitude of the continuous train of triangular pulses is apparently altered in accordance with the instantaneous values of a hypothetical signal, which exhibits pulse amplitude modulation (PAM). In addition to sampling in amplitude, this scheme apparently provides sampling in time, representing pulse width modulation (PWM). A Fourier transform spectrum of this waveform shows the `carrier’ frequency and the accompanying `side bands’.

Anurup Gohain Barua¹

1. Department of Physics, Gauhati University, Guwahati 781 014, India

Published

March 2013

Manuscript received

8 August 2012

Accepted

12 December 2012