Abstract

In the last decade, femtosecond (fs) pulse technology has evolved rapidly and has allowed achieving a few-optical-cycle pulse generation directly from an oscillator. Output pulse energy from such an oscillator amounts merely few nanojoules. An obvious route to higher pulse energies is to increase the oscillator length [1], In this case the pulse energy scales as E = P_avT_cav, where T_car is the oscillator cavity period, P_av is the average power. To date, such a technology has been demonstrated for Ti:Sapphire [1] and thin-disk near-IR [2] oscillators. At very high pulse energies, operation in positive dispersion regime (chirped-pulse oscillator, CPO) proved to be advantageous [3], Advance of these technologies in the mid-infrared wavelength range beyond 2 μm is of special importance for nano- and micro-machining of photonic structures in semiconductors, wavelength conversion, as well as for continuum generation in the mid-IR. Most prospective candidates in this wavelength region are Cr-chalcogenide oscillators [4] currently providing several-optical-cycle pulse generation around 2.5 μm [5] and having a potential for single optical cycle pulse operation. In this work we analyze the stability of an energy-scalable CnZnSe oscillator and compare the limits of energy scalability in the positive- and negative-dispersion regimes.

© 2007 IEEE