Optical Frequency Comb For High-resolution And Precision Metrology

In this work we describe two optical frequency comb systems based on homemade high-repetition rate mode- locked femtosecond Ti:sapphire lasers. One of them uses a laser that has the spectrum broadened with a microstructure fiber to cover a whole optical octave. Its repetition rate can be easily adjusted form 750 MHz to 1 GHz. The other system is based in a ultra-broadband femtosecond high repetition rate Ti:sapphire laser whose spectrum covers a range from 585 nm to 1200 nm (at 20 dB below the maximum) without the use of the microstructure fibers. We have increased the repetition rate from 1 GHz to 2.12 GHz without observing any significant change in the width of the spectrum. The repetition rate of both lasers has been phase- locked to stable microwave oscillators, and could also be frequency tuned in a range of 30 kHz with respect to the reference oscillator. We are going to use these systems in a direct optical frequency measurement technique and in an optical atomic clock based on the Calcium intercombination transition at 457 THz. © 2007 IEEE.644647Udem, T., Holzwarth, R., Hansch, T.W., Optical frequency metrology (2002) Nature, 416 (14), pp. 233-237. , MarchCundiff*, S.T., Ye, J., Colloquium: Femtosecond optical frequency combs (2003) Rev. Mod. Phys, 75 (1), pp. 325-342. , JanuaryHollberg, L., WOates, C., Wilpers, G., Hoyt, C.W., Barber, Z.W., Diddams, S.A., Oskay, W.H., Bergquist, J.C., Optical frequency/wavelength references (2005) J. Phys. B: At. Mol. Opt. Phys, 38, pp. S469-S495Bauch, A., Telle, H.R., Frequency standards and frequency measurement (2002) Rep. Frog. Phys, 65, pp. 789-843. , AprilNogueira, G.T., Cruz, F.C., Efficient 1 GHz Ti:sapphire laser with improved broadband continuum in the infrared (2006) Opt. Lett, 31 (13), pp. 2069-2071. , Julyalso at Virtual Journal of Ultrafast Science, 5, no. 8, May 2006Bartels, A., Kurz, H., Generation of a broadband continuum by a Ti:sapphire femtosecond oscillator with a 1-GHz repetition rate (2002) Opt.Lett, 27 (20), pp. 1839-1841. , Octobe