| Scanning near-field optical microscope (SNOM), as a kind of new important optical apparatus that is used to observe appearance or investigate immanent essence of sub-wavelength objects , has been played a crucial role in the wide range of physics , chemistry, biology, medical science, geology, IT estate in last years . One of difficulties of conventional SNOMs is the relatively low power of out signal . This problem is solved by using vertical cavity surface emitting laser (VCSEL) feedback as the SNOM detection principle .Many kinds of VCSELs has been fabricated in the domestic and an kind of AlGaAs microtip with micrometer dimension has been successfully grown on GaAs substrate with self-organization by liquid phase epitaxy (LPE) . It was reported that a VCSEL and a Si microtip can be simply aligned together using an adhesive agent .hi this article , the peculiarity of VCSEL has been observed and investigated . According to photomicrograph, the diameter of emitting aperture is about 40um . In term of I-V curve, the threshold voltage is 1.4V . Considering P-I curve , the threshold current is 2.8mA . According to far-field curves, VCSEL has the circle symmetry, the full wideth at half maximum (FWHM) is respectively 5 and 8 in two different direction . In the term of spectrum curves, the stimulating wavelength is 843.8nm and FWHM is about 2nm . All is the base work in the aspect of VCSEL that a VCSEL and a AlGaAs microtip can be integrated and established as a VCSEL/SNOM sensors . |
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