Amplitude-squared squeezing in the kth harmonic generation

Squeezing of the square of the field amplitude in second harmonic generation

Squeezing of the kth power of the field amplitude

Amplitude-cubed squeezing in harmonic generations

Higher order amplitude squeezing in fourth and fifth harmonic generation

Observation of amplitude squeezing of the up-converted mode in second harmonic generation

Phase properties of field modes in the process of kth harmonic generation