Semiconductor Laser Threshold Current Evaluation from I-L Curve Intersections

The patent applies dynamics by making the evaluation method adaptive rather than static. The algorithm dynamically adjusts the straight line construction based on local I-L characteristic shapes, identifying optimal measurement points through differential coefficient analysis. This allows the same algorithm to accurately evaluate threshold currents across lasers with varying characteristics without requiring manual intervention for each case.

The patent changes the evaluation parameter from fixed two-point intersection to a variable approach using differential coefficients (dL/dI and d2L/dI2). By calculating differential coefficients at multiple points and identifying peak positions, the method adapts to different I-L characteristic shapes. The threshold current is determined by finding where the straight line through peak points intersects the X-axis, providing accurate evaluation across varying laser characteristics.

The patent creates a universal evaluation algorithm that works for all semiconductor lasers regardless of their specific characteristics. The method uses differential coefficient analysis to identify characteristic points in the I-L curve, then constructs straight lines through these identified points. This single algorithm reliably evaluates threshold currents for lasers with standard or non-standard characteristics, eliminating the need for separate verification procedures for each laser type.

The evaluation method performs self-verification through its internal logic. By calculating differential coefficients, identifying peak positions, and constructing straight lines through these objectively determined points, the algorithm automatically ensures its own accuracy without requiring external manual verification. The method's structure inherently adapts to each laser's characteristics while maintaining consistent evaluation standards.

The patent makes the algorithm dynamic by using differential coefficient analysis to automatically identify characteristic points in each I-L curve. Rather than relying on fixed geometric constructions, the method calculates dL/dI and d2L/dI2, identifies peak positions, and constructs straight lines through these dynamically determined points. This allows the same algorithm to adapt to each laser's specific characteristics while maintaining operational simplicity.

The patent transforms the evaluation approach by changing from fixed geometric parameters to variable parameters based on differential coefficients. The algorithm uses peak positions of dL/dI and d2L/dI2 as variable parameters that automatically adjust to each laser's I-L characteristic shape. This parameter change enables accurate threshold current evaluation for both standard and non-standard lasers using a single algorithm.