No abstract

Temporal optical soliton molecules were recently demonstrated; they potentially allow further increase of data rates in optical telecommunication. Their binding mechanism relies on the internal phases, but these have not been experimentally accessible so far. Conventional frequency-resolved optical gating techniques are not suited for measurement of their phase profile: Their algorithms fail to converge due to zeros both in their temporal and their spectral profile. We show that the VAMPIRE ͑very advanced method of phase and intensity retrieval of E-fields͒ method performs reliably. With VAMPIRE the phase profile of soliton molecules has been measured, and further insight into the mechanism is obtained.

A self-referencing technique for measuring amplitude and phase of ultrashort laser pulses is presented. In contrast to the other methods the relative-phase ambiguities do not appear in our method. Thus, we can characterize ultrashort pulses with well-separated frequency components. The relative-phase ambiguities can be avoided by the use of a cross-correlation technique with two independent laser pulses. Further we propose and demonstrate experimentally a new realtime phase-retrieval algorithm that reconstructs both pulses fast and uniquely.

The phase retrieval problem is of wide interest because it appears in a number of interesting application areas in physics. Several kinds of phase retrieval problems appeared in laser optics over the past decade. In this paper we consider the numerical solution of two phase retrieval problems for an unknown smooth function f with compact support. We approximate f by a linear spline. The corresponding spline coefficients are iteratively determined by local Gauss-Newton methods, where convenient initial guesses are constructed by a multilevel strategy. We close with some numerical tests which illustrate our method.