| 摘要 |
PURPOSE:To remarkably shorten the man-hour for a measuring evaluation by applying a calculation processing to a characteristic which has been measured by using an injection current-optical output characteristic and an injection current-differential optical output characteristic. CONSTITUTION:Between an element for showing a single axis mode oscillation characteristic, and an element for showing a multiaxis mode oscillation characteristic, a difference is seen in an optical output injection current (L-I) characteristic, therefore, by utilizing a difference of this L-I characteristic, the element is selected roughly. In the vicinity of an oscillation threshold value, the L-I characteristic is pretty roundish. This characteristic is displayed by a graph by a differential optical output (dL/dI) - current (dL/dI-I) characteristic by taking a differentiation against a current of an optical output. On the other hand, when the same characteristic is measured with regard to the element which is oscillated by a single axis mode, the L-I characteristic is small in its roundness in the vicinity of the oscillation threshold value, the natural emission is migrated suddenly to a laser oscillation of an induced emission. When this characteristic is evaluated by the dL/dI-I characteristic, a value of dL/dI before the oscillation threshold value is decreased remarkably, comparing with the case of a multiaxis mode laser. Accordingly, by discriminating a difference of such a characteristic before the oscillation threshold value, the element for executing a single axis mode operation is selected roughly.
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