Strong-Field Above-Threshold Photoemission from Sharp Metal Tips
Strong-Field Above-Threshold Photoemission from Sharp Metal Tips
We present energy-resolved measurements of electron emission from sharp metal tips driven with low energy pulses from a few-cycle laser oscillator. We observe above-threshold photoemission with a photon order of up to 9. At a laser intensity of 2*10^11 W/cm^2 suppression of the lowest order peak occurs, indicating the onset …