Wideband-tuneable, nanotube mode-locked, fibre laser
Summary (1 min read)
F. WANG1, A. G. ROZHIN1, V. SCARDACI1, Z. SUN1, F. HENNRICH2, I. H. WHITE1, W. I. MILNE1 AND A. C. FERRARI1*
- Even for a wavelength detuning of up to 200 nm from the peak resonance, appreciable saturable absorption can still be observed25.
- Thus, the authors study the mode-locking of the current laser over the extended wavelength range 1,518–1,565 nm in order to achieve the maximum possible tuning range.
- An average pulse duration of 2.39 ps is obtained for different wavelengths (Fig. 4a).
SWNTs COMPOSITE
- The SWNT–polycarbonate composite was prepared first by dispersing SWNT powders in dichlorobenzene (DCB) in the presence of poly(3-hexylthiophene- (Dashed line, optical spectrum without bandpass filter; dotted line; Er3þ fluorescence spectrum).
- The use of the bandpass filter means that the output spectra have a high signal-to-noise ratio of 50 dB ( 105 contrast).
- Nature nanotechnology | VOL 3 | DECEMBER 2008 | www.nature.com/naturenanotechnology740 © 2008 Macmillan Publishers Limited. 2,5-diyl) (P3HT) by ultrasonication (Diagenode SA).
- No SWNT bundles could be detected under the scrutiny of an optical microscope, thus ensuring minimized scattering losses.
POWER-DEPENDENT ABSORPTION MEASUREMENTS
- Power-dependent absorption measurements were carried out as follows.
- This was achieved by filtering a commercial femtosecond fibre laser (200 fs, 76.9 MHz, TOPTICA) using a 3-nm band-pass filter.
- The laser beam was amplified by an erbium-doped fibre amplifier and a 10% tap was used to monitor the input power to the mode-locker assembly, containing their composite, and two appropriately calibrated powerheads were programmed to read the input/output power simultaneously.
TUNEABLE LASER EXPERIMENTAL SETUP
- The mode-locker was assembled by sandwiching the free-standing SWNT composite between two fibre ferrules inside a physical contact ferrule connector.
- The estimated input mode diameter on the composite was 10 mm.
- Two isolators were placed at both ends of the amplifier section to maintain unidirectional laser operation.
- When the pump power was increased to 45 mW, stable mode-locking could be initiated by introducing a disturbance to the polarization controller.
Author information
- Reprints and permission information is available online at http://npg.nature.com/reprintsandpermissions/.
- Correspondence and requests for materials should be addressed to A.C.F. nature nanotechnology | VOL 3 | DECEMBER 2008 | www.nature.com/naturenanotechnology742 © 2008 Macmillan Publishers Limited.
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