| 摘要 |
An efficient multi-emitter boresight reference source (12). The efficient reference source (12) includes a first mechanism (182) for transmitting a first portion of electromagnetic energy (184) within a first waveband. A second mechanism (186) transmits a second portion of electromagnetic energy (188) within a second waveband different than the first waveband. A third mechanism (148) for combining the first portion of electromagnetic energy and the second portion of electromagnetic energy to yield a uniform reference beam (28). In a specific embodiment, the first mechanism (182) includes a first emitting structure (182), and the second mechanism (186) includes a second emitting structure (186). The first emitting structure (182) and the second emitting structure (186) are semiconductor laser emitting structures. The first waveband (184) and second waveband (188) correspond to wavebands of one or more sensors employing the boresight reference source (12) for beamalignment purposes. The wavebands (184, 188) include visible and/or infrared portions of the electromagnetic spectrum. The first waveband (184) and second waveband (188) are sufficiently different to eliminate undesirable coupling between first and second laser cavities (182, 186) associated with the first and second emitting structures (182, 186), respectively. The uniform reference beam (28) is a collimated, co-aligned, and multi-spectral reference beam (28), and at least one of the first and second emitting structures (182, 186) includes a Quantum Cascade Laser (QCL) emitting structure. The first emitting structure (182) includes multiple QCL repeat units within a common waveguide region of the first emitting structure (182). The multiple QCL repeat units have different superlattice compositions and/or quantum well thickness, sufficient to cause the first emitting structure (182) to operate at different wavelengths to enhance uniformity of the uniform reference beam (28). The multiple QCL repeat units may also be identical repeat units operating at different temperatures to generate different center wavelengths within each waveband (184, 188). Alternatively, the first emittting structure (182) includes multiple identical QCL
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