MULTI-WAVELENGTH SURFACE EMITTING LASER ARRAY

大规模集成的并行光器件在未来的并行光纤通信系统、光互连、并行光记录等方面有着重要的应用前景，垂直腔面发射激光器（VCSEL）由于其低阈值和易于与光纤耦合等优点，在光互连和高速并行光数据链方面受到广泛关注。2-D阵列配置将增加光学互连中的连接密度。此外，如果多波长VCSEL阵列可用于波分复用（WDM）互连，则可以预期诸如波长路由的功能。垂直腔面发射激光器在波分复用系统中的一个潜在应用是多波长激光器阵列，其激射波长主要由腔的长度、等效折射率和横向尺寸决定。其中，激射波长主要取决于腔长。为 关于我们 例如，在1 μ m的标称波长下，晶片上层厚度的1%变化产生10 nm的相当大的波长变化。如果我们能够局部控制层的厚度，我们可以形成多波长的2-D阵列，以及补偿整个晶片的激光波长的不均匀性。提出了一种利用非平面分子束外延（MBE）生长来局部控制多波长VCSEL阵列的层厚的方法，并提出了一种利用非平面金属有机化学气相沉积（MOCVD）实现VCSEL在片波长控制的新技术。除了在生长之前对衬底进行图案化之外，制造过程与标准VCSEL的制造过程相同。多波长VCSEL阵列可以通过改变圆形图案的尺寸来制造。利用该技术实现了低阈值3 × 3多波长VCSEL阵列。该方法可用于实现具有极大波长跨度的多波长VCSEL阵列。此外，我们将能够通过使用这种技术来补偿VCSEL在大晶片上的波长不均匀性。少

Massively integrated parallel optical devices are becoming important for use in future parallel optical fiber communication systems, optical interconnects, parallel optical recording and so on. Vertical cavity surface emitting lasers (VCSELs) have been attracting much interest for optical interconnects as well as for hihg speed parallel optical data links because of their low threshold and ease in optical coupling to fibers. A 2-D array configuration will increase the connection density in optical interconnects. In addition, if multi-wavelength VCSEL arrays are available for wavelength division multiplexing (WDM) interconnects, functionalities such as wavelength routing can be expected. A potential application of VCSELs for WDM systems is multi-wavelength laser arrays.The lasing wavelength of VCSELs is determined primarily by the length, the equivalent refractive index and the lateral size of the cavity. Among them, the lasing wavelength predominantly depends on the cavity length. For … More example, a 1% variation of layr thickness over a wafer produces a fairly large wavelength change of 10nm at a nominal wavelength of 1mum. If we are able to locally control the layr thickness, we can form multi-wavelength 2-D arrays as well as compensate for the nonuniformity of the lasing wavelength across the wafer. A nonplanar MBE growth is proposed as a way of local control of layr thickness for multi-wavelength VCSEL arrays.In this work, we present a novel technique of on-wafer wavelength control of VCSELs using nonplanar metalorganic chemical vapor deposition (MOCVD). The fabrication process is the same as that of standard VCSELs except that the substrates are patterned prior to the growth. Multi-wavelength VCSEL arrays can be fabricated by changing the size of the circular pattern. Low threshold 3*3 multi-wavelength VCSEL arrays were demonstrated by using this technique. The proposed method might be useful to realize muti-wavelength VCSEL arrays with an extremely large wavelength span. Also, we will be able to compensate for the wavelength nonuniformity of VCSELs across a large wafer by using this technique. Less