Fig. 1. Three kinds of dielectric materials with dielectric constants arranged periodically^[3]. (a) 1-D; (b) 2-D; (c) 3-D

Fig. 2. Photonic band gap

Fig. 3. Relationship between wave number and frequency of photonic crystal materials

Fig. 4. Optical cavity. (a) Optical cavity structure; (b) standing wave in optical cavity

Fig. 5. 2^nd order grating distributed feedback laser^[5]. (a) Cross section; (b) diffraction characteristics

Fig. 6. Band structure of two-dimensional triangular lattice photonic crystal^[6]

Fig. 7. Light cone structure

Fig. 8. Light cone in band diagram^[6]

Fig. 9. Two-dimensional photon crystal^[7]. (a) Structure chart; (b) reciprocal lattice

Fig. 10. Dispersion relationship and coupling wave propagation direction^[7]. (a) Dispersion relation of electromagnetic waves propagating in two-dimensional photonic crystal; (b) propagation direction of coupled waves at points I-IV

Fig. 11. Wave vector diagrams of points I and II^[7]. (a) Wave vectors at point I; (b) wave vectors at point II

Fig. 12. Diffraction wave vectors occurring at point III^[7]. (a) Diffraction wave vectors in plane;(b) diffraction wave vectors perpendicular to plane of photonic crystal

Fig. 13. Diffraction wave vectors of point IV in different directions^[7]. (a) In-plane of photonic crystal; (b) vertical direction; (c) out-of-plane tilt direction

Fig. 14. Structure diagram of a two-dimensional triangular lattice surface emitting laser based on wafer fusion technology^[9]

Fig. 15. Structure of electrically injected PCSEL^[11]. (a) Schematic of cross-section; (b) tilted-angle crosssectional image from scanning electron microscope; (c) top-view image

Fig. 16. PCSEL characterization results^[11]. (a) Power-current-voltage curves of quantum dot photonic crystal laser; (b) spectral characteristics

Fig. 17. Schematic of silicon-based PCSEL^[12]

Fig. 18. Characterization results of lasers operating under 965 nm band^[13]. (a) Far-field divergence angle; (b) current-power caracteristic curve

Fig. 19. GaN-based InGaN quantum well PCSEL structure^[14]. (a) Schematic structure of GaN-based PCSEL; (b) triangular lattice air holes; (c) scanning electron microscope image of PCSEL cross section

Fig. 20. GaN-based InGaN quantum well PCSEL characterization results^[14]. (a) Current and optical output power characteristics at room temperature; (b) emission spectra at different threshold currents

Fig. 21. PCSEL structure diagram^[15]

Fig. 22. Scanning electron microscope images ofdifferent photonic crystal structures^[15]

Fig. 23. Schematic of photonic crystals with different boundary shapes^[15]

Fig. 24. Fabrication and characterization of InGaN nanocrystal surface-emitting laser diodes^[17]. (a) Nanocrystal surface-emitting laser PCSEL; (b) current-voltage characteristics of laser; (c) electroluminescence spectra of different injection currents under continuous current conditions at room temperature; (d) variation curve of output power and injection current

Fig. 25. Schematic of PCSEL structure with DBR^[23]

Fig. 26. PCSEL characterization results of DBR^[23]. (a) Power-current characteristic of PCSEL array; (b) spectrum of PCSEL

Fig. 27. Comparison of radiation constants with or without vertical asymmetric air hole structure^[25]

Fig. 28. Schematic of PCSEL structure and scanning electron microscope images of photonic crystal^[25]. (a) Schematic of PCSEL structure, arrows indicate rowth direction of first and second epitaxy; (b) top view electron micrograph of square lattice photonic crystal before using MOCVD for second epitaxy; (c) second cross-sectional scanning electron micrograph of photonic crystal air hole after epitaxy

Fig. 29. Upper attempt and left view of single air hole structure approximating triangular prism and triangular pyramid^[25]

Fig. 30. Light intensity distribution in photonic crystal cavity^[24]. (a) Single air hole unit with area 10 times larger than experimental device; (b) double-hole cell structure with the same area as (a)

Fig. 31. Double pore structure diffraction^[24]. (a) Plane diffraction; (b) vertical diffraction

Fig. 32. Schematic of two-dimensional photonic crystal laser structure^[24]

Fig. 33. Current-power characteristic curve^[24]

Fig. 34. PCSEL structure diagram^[27]

Fig. 35. Schematic diagram of elliptic double lattice structure^[27]

Fig. 36. Laser characterization results of asymmetric structure^[27]. (a) Current-power characteristic curve; (b) spectrum of current at 1000 mA

Fig. 37. Double lattice photonic crystal laser structure^[28]. (a) Scanning electron microscope image of double lattice photonic crystal; (b) scanning electron microscope image of PCSEL cross-section; (c) physical picture after packaging

Fig. 38. Current-power characteristic curves of laser at different temperatures^[28]

Fig. 39. Photonic crystal cavity and coupling cavity with FP^[31]. (a) Loss of energy at edge of photonic crystal region; (b) structure introduced into FP cavity

Fig. 40. Schematic structure of LC-PCSEL^[32]

Fig. 41. Power-current-voltage curves and deep hole cross section of LC-PCSEL device^[32]

Fig. 42. Surface-emitting spectrum of LC-PCSEL^[32]

Fig. 43. Light-current-voltage curves of LC-PCSEL^[33]

Fig. 44. PCSEL based on WS235

Fig. 45. Band structure of two-dimensional photonic crystal composed of square lattice and round pores^[36]

Fig. 46. Band structure of two-dimensional photonic crystal^[31]. (a) Photonic band of triangular lattice with flat band structure is obtained by adjusting radius; (b) near point Γ₂ band structure

Fig. 47. Group velocity of band B^[31]

Fig. 48. Three-dimensional band diagram

Fig. 49. 1^st Brillouin region of two dimensional triangular photoniccrystal^[31]

Fig. 50. 1.3 μm InAs/GaAs quantum dot PCSEL structure diagram and scanning electron microscope image of photonic crystal^[31]. (a) Schematic of structure principle; (b) plan view of structure; (c) top view of photonic crystal; (d) top view and plan view of photonic crystal; (e) physical diagram of laser

Fig. 51. Varying temperature current-power characteristic curves of PCSEL under pulse current condition^[31]

Fig. 52. Variable temperature current-power characteristic curves of PCSEL under condition of continuous current^[31]

Fig. 53. Schematic of topological posture laser^[37]. (a) Triangular nanopoires are moved away from or towards centers of each structure to form topological and trivial photon energy bands, respectively; (b) bands of topological and trivial photonic crystals when they contact in real space; (c) vertically emitting topological posture lasers

Fig. 54. Performance of topological posture laser^[37]. (a) Spectrum of wavelength varying with power; (b) fitting curve of relationship between output power and pump strength; (c) maser spectrum

Fig. 55. Comparison of maximum output power per unit area of electro-pumped lasers with different device structures under pulsed current at room temperature