Abstract ▼ AI-Helper

The vertical-cavity-surface-emitting-laser (VCSEL) has emerged as the light source for modern high speed and short wavelength communication systems. A VCSEL with high speed and wavelength of 850 nm is required for future high-capacity and short-reach communication link. The wavelength of 850 nm is t...

The vertical-cavity-surface-emitting-laser (VCSEL) has emerged as the light source for modern high speed and short wavelength communication systems. A VCSEL with high speed and wavelength of 850 nm is required for future high-capacity and short-reach communication link. The wavelength of 850 nm is the standard wavelength in data communication industry. It has also several advantages compared to longer wavelength. In this study, a 850 nm VCSEL which operates with the speed of 10 Giga bit per sec (Gbps) at room temperature and 85 ℃ is demonstrated. The VCSEL structure was grown by metal-organic chemical vapor deposition (MOCVD) system. Four different type of the sample with different current aperture size were studied. VCSELs with a small current aperture size have low threshold current, rapid rollover, and high dynamic resistance. Threshold current increases from 0.4 mA to 1.35 mA with the aperture size. As temerature increases, maximum output power and slop efficient decrease. These characteristics were identified by eye diagram measurement at 85 ℃ as well as room temperature. The sample with 12 ㎛ current aperture size operate at 4.25 Gbps. However, it has difficulty of operation at 10 Gbps mainly due to over shoot and abnormal eye pattern. The other three sample with 7 ㎛, 8 ㎛, 9 ㎛ current aperture size exhibit comparable characteristics at room temperature, but show different results at high temperature. Two sample with 7 ㎛ and 8 ㎛ current aperture size were not able to operate at 10 Gbps because the optical power was saturated at 75 ℃ and 82 ℃, respectively. For the sample with 9 ㎛ current aperture size, it shows the error free operation at 10 Gbps at room temperature and high temperature, which was confirmed by stability of eye pattern.

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