Temperature activated mirror-less laser action from a hole-transport conjugated-polymer

Abstract

A plethora of experimental reports and evidences from recent times have collectively taken efforts in developing a novel mirror-less laser. Breakthrough in Conjugated polymer lasers unravel numerous attractive research direction over the last decade. The present study experimentally demonstrated a temperature-activated/controlled amplified spontaneous emission (ASE) in a hole-transport conjugated polymer (HTCP) Poly[N,N’-bis(4-butylphenyl)-N,N’-bis(phenyl)-benzidine] [poly-TDP (4B)]. The poly-TDP (4B) dissolved in toluene under wide range concentration. The solution of different concentration was pumped with an Nd:YAG (355 nm) laser. For temperature lower than 37 °C, the poly-TDP (4B) did not produce ASE, but for the 40 °C, the ASE is observed. Furthermore, the output energy of the ASE is dependent on the temperature of the solution. The ASE output energy attains maximum at a temperature of 78 °C, and then the output falls drastically. The time-resolved spectroscopy studies showed the temperature responsiveness of the HTCP poly-TDP (4B) in the sub-nanosecond time domain. The temperature-dependent laser action is due to reversible dimerization property of the poly-TDP (4B), and it is rare.