Novel spin-polarized electron source using a non-linear optical absorption

2015 Fiscal Year Final Research Report

• Project/Area Number: 25706031
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Quantum beam science
• Research Institution: Nagoya University
• Principal Investigator: Kuwahara Makoto 名古屋大学, 未来材料・システム研究所, 准教授 (50377933)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: スピン / 量子ビーム / 量子光デバイス / 非線形光学効果

Outline of Final Research Achievements

We have researched a possibility of a novel spin-polarized electron source using a two-photon absorption. A nitride semiconductor was used for the substrate of NEA-photocathode to realize high quantum efficiency, long lifetime and tiny emission spot which contributed to a beam quality such brightness and emittance. We have succeeded in development of a newly designed photocathode that consists of InGaN-GaN superlattice optimized for the two-photon absorption. Detection system for pulsed electron-beam and optical system were constructed and used for the excitation of spin-polarized electron. Experimental results indicated that two-photon absorption occurred in the fabricated photocathode. The nonlinear absorption let the emission spot smaller than that of one-photon absorption, which generates a low initial emittance. We have demonstrated that the novel photocathode with the nonlinear photo-excitation will provide a high quality electron beam and a high stability of electron emission.

Free Research Field

電子顕微鏡