MEASURING METHOD FOR TOTAL LIGHT OUTPUT OF SEMICONDUCTOR LIGHT EMITTING ELEMENT BY CALORIMETER SYSTEM

摘要

PURPOSE:To measure exactly the absolute value of the total light output of a semiconductor light emitting element irrespectively of the wavelength by measuring the total light output of the optional semiconductor light emitting element as a part of the thermal load of a calorimeter. CONSTITUTION:Electric current is supplied to a semiconductor light emitting element 12 and a thermoelectric cooling element 16 and thereafter the heater power Ph of the heater 13 of a load 15 is controlled then the internal temp. T1 of a jacket 11 and the temp. T2 of the load 15 are so controlled by a controller 20 for DC power that the relation between said temps. attains T1=T2. The electric power in this atage is designated as Ph1. The relation among the total light output P1 of the element 12, the heater power Ph1 and the power consumption Pd of the element 12 is expressed by the equation (1). Without application of current to the element 12, the power of the heater 13 is so controlled by the controller 20 that the temp. T2 of the load 15 and the internal temp. T1 of the jacket 11 are made equal. The power in this stage is designated as Ph2. The relation between the power Ph2 and the cooling power Pc is expressed by the equation (2). The total light output P1 of the element 12 is like the equation (3) by the equation (1) and the equation (2).