  We report measurements of the optical responses of a La2/3Sr1/3MnO3 (LSMO)
sample at a wavelength of 533 nm in the 300-400 K range. The 200 nm thick film
was grown by pulsed laser deposition on (100) SrTiO3 substrate and showed
remarkably low noise. At 335 K the temperature coefficient of the resistance of
a 100 micrometers wide 300 micrometers long LSMO line was 0.017 K-1 and the
normalized Hooge parameter was 9 e-30 m3, which is among the lowest reported
values. We then measured an optical sensitivity at I = 5 mA of 10.4 V.W-1 and
corresponding noise equivalent power (NEP) values of 8.1 e-10 W.Hz-1/2 and 3.3
e-10 W. Hz-1/2 at 30 Hz and above 1kHz, respectively. Simple considerations on
bias current conditions and thermal conductance G are finally given for further
sensitivity improvements using LSMO films. The performances were indeed
demonstrated on bulk substrates with G of 10-3 W.K-1. One could expect a NEP
reduction by three orders of magnitude if a membrane-type geometry was used,
which makes this LSMO device competitive against commercially available
uncooled bolometers.
