tailieunhanh - Advances in optical and photonic devices Part 3

Tham khảo tài liệu 'advances in optical and photonic devices part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Photonic Quantum Ring Laser of Whispering Cave Mode 31 As shown in the schematic Fig. 16 a tapered single mode fiber tip about 300nm in diameter was made by chemical etching for the photon collection and a step motor generates relative motions of the tip against probed PQR laser device. The collected photon signal goes through single photon counting module photon counter and computer. Home-built 2D 3D single photon scanning system Microscope with CCD Photon counter Tapered SMF core t lpm Step motor controller Computer LABVIEW program Resolution pm step Fig. 16. A schematic diagram of home-built 2D 3D single photon scanning system. Figure 17 shows some 2D scan results over a scan area of 60x60 um square where on the surface of the PQR Fig. 17 a exhibits that the emission pattern of the PQR beam is Laguerre Gaussian for the case of a mesa PQR and Fig. 17 b shows another Laguerre Gaussian pattern for the case of hole PQRs. Fig. 17. a Lagurre Gaussian beam of the mesa PQR b Lagurre Gaussian beam of the hole pQr 8. Fabrication of micro collimators for PQR beam guiding Laser printers with mechanically rotating polygon mirrors have been used widely in offices whereas new LED printers quiet and all-electronic drive circuitry with no moving parts begin to replace them. However the LED being a spontaneous emission device with some disadvantages as stated earlier can further be replaced by an efficient laser like the PQR laser diode with extremely low threshold currents and y ĩ -dependent thermally stable spectral properties which are good for fast high density array applications. Moreover typical LED printers use selfoc-lens arrays SLAs to concentrate and guide individual light 32 Advances in Optical and Photonic Devices but the expensive SLA technology is complicated. We note that the PQR laser with the micro collimator MC for non-parallel to parallel beam guiding described previously may replace the LED SLA technology. In order to find such a possibility we will now .