| 摘要 |
An optoelectronic semiconductor device (100) includes a laser (10) which emits a first radiation beam (80) with a first wavelength ( lambda 1) at one side (50) and which forms a radiation waveguide (3) for a second radiation beam (90) with a second wavelength ( lambda 2) greater than the first wavelength ( lambda 1), which second beam can enter the laser (10) at said side (50), and a photodiode (20) present at the other side (60) of the laser (10), aligned with the laser (10), and sensitive to radiation of the second wavelength ( lambda 2). The laser (10) and the photodiode (20) are discrete components which are present in series along a single, straight radiation path, and the device (100) is provided with means (51, 61, 71) whereby during use the major portion of the emission of the laser (10) is formed by the first radiation beam (80), substantially exclusively the first radiation beam (80) issues from the first side (50) of the laser (10), and substantially the entire second radiation beam (90) is capable of reaching the photodiode (20). Such a device is simple and easy to manufacture, while it can nevertheless be satisfactorily used in a glass fibre communication system. The individual components are simple and comparatively inexpensive. The means preferably include a first coating (51) on the one side (50) of the laser (10), having a low reflection at both wavelengths, and two further, multilayer coatings (61, 71) situated at the other side (60) of the laser (10), on this laser and on the photodiode (20), respectively, and having a high reflection at the first wavelength and a low reflection at the second wavelength. |
