Terahertz (THz) emission from argon cluster plasma, generated by intense femtosecond laser pulse with an energy of 10mJ, has been investigated. The angular distribution of THz was measured precisely to discuss the emission property. The highest THz power was detected at ±30° with respect to the laser propagation direction. In a comparison of the energy of THz radiation generated from argon clusters with that from argon gas, an enhancement of two orders of magnitude has been observed. Further enhancement of THz emission by optimizing laser pulse duration has been found. The findings indicate that plasmas produced from atomic clusters hold considerable promise as intense THz sources.
