def LASERpattern(period, rep):
    """function that creates a pattern imitating pulsed laser excitation
        rep - pulses within the pattern
        period between the pulses is in ns
    """
    pattern_las = [(1, 1), (period-1, 0)]
    for i in range(1,rep):
        pattern_las.append((1, 1))
        pattern_las.append((period-1, 0))
    return pattern_las