Nonlinear effects produced by Raman maser radiations.

A systematic study was made of the second harmonic generations and the mixings of the Raman lines produced in cyclohexane, acetone, benzene, and carbon disulfide. In our experimental setup, the Raman cell was placed outside the optical cavity. The second harmonic of the first-order Stokes radiation was directly photographed. In the case of cyclohexane, the diameter of the focused second harmonic corresponded to an angular spread of about 2 or 3 x 10(-2) rad. The power produced in the SHG was more than 1 kW. The spectrographic study shows that the SHG and the mixings of various Raman lines are efficient. Their details are outlined in the case of individual liquids. In terms of cyclohexane, the SHG and the mixings of Raman emissions produced from the other molecular vibration (801 cm(-1)) are also observed. The reported observations indicate that the Stokes lines, beyond first order, produced in a forward direction with a threshold condition, are strong enough to show these nonlinear effects.