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Single and multiphoton absorptions in wide band gap semiconductors determine the functionality of photodetectors, lasers, and light-emitting diodes (LEDs). Although electronic structure strongly influences the different orders of multiphoton absorptions in semiconductors, it has not been feasible to quantify their contributions on the functionality of devices. A lack of proper measurement techniques has been the hurdle. Here, we present a simple and sensitive method based on the phase modulation of femtosecond pulses to quantify single-, two-, and three-photon absorptions in GaP and InGaN photodetectors. Our results show that only three-photon absorption contributes to the photocurrent in the InGaN device when excited by femtosecond pulses at 1030 nm. On the other hand, single-, two-, and three-photon absorptions have comparable contributions in the GaP detector. The three contributions have different origins: linear photocurrent is attributed to the absorption by the impurities in the doped regions, two-photon photocurrent is from the phonon-assisted indirect transition from the valence band to the conduction band minimum, and three-photon photocurrent is from the direct transition to the conduction band. We also demonstrate that the method can be applied to image the heterogeneity of multiphoton photocurrent in devices. Our work could be adapted for “in operando” characterization of optoelectronic systems.

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The question of how to define the legal status of marine genetic resources (hereinafter MGRs) in areas beyond national jurisdiction (hereinafter ABNJ) is one of the important issues in the negotiation of the International Legally Binding Instrument under United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biodiversity of Areas beyond National Jurisdiction. According to the theory of the order and justice value of the law, in combining the experiences of the international community in handling global ocean problems and characteristics of MGRs in ABNJ, it can be said that MGRs in ABNJ have the legal attribute of being the common heritage of mankind (hereinafter CHM). From the perspective of the principle of CHM, in applying the subject, object and content elements of legal relations as the research approach, the legal status of MGRs in ABNJ should be defined as follows: Firstly, an international management body should be established and the scope of actual resource developers should be defined in terms of subject elements. Secondly, the temporal scope, geographical scope and material scope of MGRs in ABNJ should be clarified in terms of object elements. Thirdly, the disposition of rights and obligations in the process of development and utilization of MGRs in ABNJ should be defined in terms of content elements.