Dingsan Gao

Terraced substrate inner stripe visible semiconductor laser and its arrays

Lasers emitting in the range of 7500-7800 AA, which have average current thresholds of 30-40 mA and maintain single transverse mode operation up to 20 mW, are reported. Life tests show that the lasers have almost no threshold change after 3000 h of aging at 4-mW CW operation. The terraced substrate inner stripe laser arrays have clean single-lobe far-field patterns with full width at half power of 6 degrees in CW operation and 2.4 degrees in pulsed operation. >

High efficiency top surface‐emitting lasers fabricated by four implantation using tungsten wire as mask

We report the results of a high efficiency room temperature continuous wave (cw) vertical‐cavity surface‐emitting laser. The structure is obtained by four deep H+ implantation using tungsten wires as the mask. The fabrication process is the simplest ever reported in vertical‐cavity surface‐emitting laser fabrication. The largest differential quantum efficiency of 65% and maximum cw light output power over 4 mW have been achieved for the 15×15 μm2 device.

Single longitudinal mode, symmetrical three-cavity GaInAsP/InP lasers

Two ways of improving the mode-selection characteristics of diode lasers are analysed. The mode-selection mechanism and technological processes are presented for symmetrical three-cavity lasers, and the experimental results are in good agreement with theoretical results.

Vertical-cavity surface-emitting laser fabricated by two implantations using tungsten wires as mask

The design and fabrication of a room-temperature continuous wave (cw) vertical-cavity surface-emitting laser is reported. The device was fabricated by two deep H+ implantations using parallel tungsten wires as the resist mask. The direction of the mask in the first implantation is perpendicular to that in the second. The fabrication process is the simplest ever reported for vertical-cavity surface-emitting laser fabrication. A lowest threshold current of 17 mA and a maximum light output power of 4 mW were obtained.

Low resistance and large current range CW single-mode top surface-emitting laser with small window

We report the results of a room-temperature CW top surface-emitting laser whose light-emitting window is much smaller than the current injection area. The lowest series resistance of device is 50 Ω. It maintains single transverse mode at high current levels.

A novel structure of visible semiconductor lasers

Terraced substrate inner current stripe lasers emitting in the range of 750–780 nm are developed with very simple fabrication processes. The lasers have good performance of cw room temperature, linear light-current output over 30 mW per facet and maintain stable fundamental transverse and longitudinal mode of 2–4 times current threshold. The current threshold of 25 mA under cw room temperature operation has been achieved.

Trapezoidal channeled substrate inner stripe phase-locked semiconductor laser arrays

A novel type of trapezoidal channeled substrate inner stripe diode laser array grown by single‐step liquid‐phase epitaxy was designed and fabricated. A six‐element array with evanescent wave coupling, as well as leaky wave coupling, shows a continuous‐wave threshold current of 170 mA and a pulsed peak power over 675 mW per facet without a coating. A clean single‐lobe far‐field pattern of beam width 2.4° is obtained.

Terraced substrate inner stripe semiconductor lasers by one‐step liquid‐phase epitaxy

A new (GaAl)As/GaAs laser with low threshold current and a single mode is developed. By making use of selective growth properties of liquid‐phase epitaxy over a nonplanar substrate, the growth of all layers and an inner stripe for a current channel are completed by one‐step liquid‐phase epitaxy. This allows for a very simple fabrication process.

Influence of annealing on optical properties of ZnO film

No annealed, annealed after growth and annealed during growth ZnO films (denoted s1,s2, and s3 respectively) were grown on C-plane sapphire substrate by plasma-enhanced MOCVD and characterized by XRD and the optical transmission spectra. We could find that there is tensile strain in the c-plane of the films. Furthermore, the tensile strain increases after annealing. At the same time, the optical transmission indicates that the transmission of s2 in visible region is the highest and the value of s3 is the lowest.

Channelled substrate window twin stripe GaAs/GaAIAs visible lasers: fabrication and steady-state analysis

GaAs/GaAIAs high-power window stripe lasers have been developed with a uniform active layer in the region adjacent to the device facets and with a curved active layer in the central region. A single-step liquid-phase epitaxy growth is used in the fabrication process to form two internal lateral current paths, so allowing for a very simple fabrication process. The optical coupling between the two stimulation emission regions reduces the beam divergence. The steady-state analysis of such a laser structure, including heating effects, agrees well with experimental results.