摘要:
Consistent with the present disclosure, the number of passive waveguides in a PIC are reduced by directly connecting active components to one another. Accordingly, optical signals propagating in the PIC may experience less loss, and, thus, improved performance may be achieved. In addition, active components may be bent or curved in order to obtain a more compact layout with greater device density. Reduced manufacturing costs can therefore be realized.
摘要:
A multimode interference coupler having a tunable power splitting ratio and a method of tuning the splitting ratio. The tuning of the power splitting ratio is achieved by varying an effective refractive index around a portion in a multimode interference section.
摘要:
A hybrid integrated optical transmitter comprising a wavelength selectable laser (WSL) source coupled to an optical amplifier/modulator has been realized. Disposed between the optical combiner and the optical amplifier/modulator is an “optical isolator.” The optical isolator includes at least a Faraday rotator and, either solely or in combination with a single polarizer and/or half-wave plate is used to selectively rotate and pass polarized light egressing from the wavelength selectable laser source. Optical isolation is achieved by the egressing radiation from and back reflections incident on the laser source being at two mutually exclusive orthogonal polarization states or by the reflections being totally extinguished. Advantageously, the laser source is unresponsive to orthogonally polarized light, and hence any unwanted back reflections do not substantially affect the operating characteristics of the laser(s). Optical isolation may be further improved, however, with the use of an additional polarizer positioned in front of the Faraday rotator to totally extinguish the polarized back reflections. Preferably, a latching Faraday rotator is used. As such, permanent magnets are not needed to maintain the latching Faraday rotator in its saturated state, and substantially reduces cost, size and complexity of the transmitter package. The wavelength selectable laser source is integrated on a single substrate with an optical combiner that directs the radiation to the optical amplifier/modulator, which is integrated on a second substrate. Alternatively, the laser source and optical combiner may be integrated on different substrates.
摘要:
A method of controlling the relative amounts of silicon dopant inside and outside of an enhanced growth region on an indium phosphide substrate using a metalorganic chemical vapor deposition (MOCVD) process. The method includes the steps of positioning the indium phosphide substrate in a reactor chamber, and defining an enhanced growth region on the substrate by depositing a dielectric mask on the substrate. The indium phosphide substrate is heated to a growth temperature of between about 600 and 630° C., and the pressure in the reactor chamber is adjusted to between about 40 and 80 Torr. A first gas contains a metalorganic compound comprising indium and a hydrogen carrier gas flow of between about 12 and 16 liters/minute, and a second gas containing a phosphide and a doping gas containing a silicon dopant at a flow rate of between are introduced into the reactor chamber. The first and second gases are mixed in the chamber and forced over the substrate in a laminar flow such that the mixed convection parameter is between about 0.31 and 0.33. An n-type indium phosphide epitaxial layer is thereby grown over the substrate by reacting the first with the second gas and thermally decomposing the carrier gas, whereby areas inside and outside of the growth enhanced region contain substantially the same amount of silicon dopant.
摘要:
A single-mode stabilized laser comprises a laser cavity having a round trip time .tau..sub.r and a linewidth enhancement parameter .alpha.; and a frequency routing device formed in the laser cavity comprising controllable frequency selective pathways such that selective gating of the frequency selective pathways causes selected lasing frequencies to be supported in the laser cavity separated by a frequency spacing .DELTA.F.sub.C, .DELTA.F.sub.C =1/.tau..sub.r. The frequency routing device has an optical grating having unequal length waveguides to form paths. The optical grating has arms, a time delay .tau..sub.f between the longest path and the shortest path, and a grating bandwidth .DELTA.F.sub.F, .DELTA.F.sub.F =1/.tau..sub.f, at least one of (1) .alpha. and (2) .tau..sub.r and .tau..sub.f having sufficient value to stabilize the laser in single-mode operation. A method of turning on a laser having a waveguide grating to a stable operating condition comprises the steps of applying an initial current to a first amplifier and maintaining a second amplifier off; allowing the laser to reach thermal equilibrium; applying an operating current to the second amplifier; and applying another operating current to the first amplifier to stably operate the laser.
摘要翻译:单模稳定激光器包括具有往返时间τr和线宽增强参数α的激光腔; 以及形成在激光腔中的频率路由装置,包括可控频率选择性路径,使得频率选择性路径的选择性选通导致选择的激光频率被支持在由频率间隔DELTA FC,DELTA FC = 1 / tau 。 频率路由设备具有具有不等长度波导的光栅以形成路径。 光栅具有臂,最长路径和最短路径之间的时间延迟τf,光栅带宽DELTA FF,DELTA FF = 1 / tau f,(1)α和(2)τr中的至少一个,以及 tau f具有足够的值以在单模操作中稳定激光器。 将具有波导光栅的激光器接通到稳定工作状态的方法包括以下步骤:向第一放大器施加初始电流并关闭第二放大器; 允许激光达到热平衡; 对第二放大器施加工作电流; 并向第一放大器施加另一个工作电流以稳定地操作激光器。
摘要:
Consistent with the present disclosure, MZ drive signal electrodes may be provided relatively close to and parallel to one another, such that the underlying waveguide arms may also be provided close to and parallel to one another. As a result, common mode performance of an MZ modulator may be obtained. In one example, an electrode wiring configuration consistent with the present disclosure may permit a waveguide arm separation of 40 microns or less.
摘要:
Consistent with the present disclosure, the number of passive waveguides in a PIC are reduced by directly connecting active components to one another. Accordingly, optical signals propagating in the PIC may experience less loss, and, thus, improved performance may be achieved. In addition, active components may be bent or curved in order to obtain a more compact layout with greater device density. Reduced manufacturing costs can therefore be realized.
摘要:
Consistent with an aspect of the present disclosure, a package is provided that has a carrier and first and second substrates provided on the carrier. Conductive traces are provided on the first substrate (upper traces) and below it (lower traces) to provide two levels of electrical connectivity to a photonic integrated circuit (PIC) provided on the second substrate. As a result, an increased number of connections can be made to the PIC in a relatively small package, while maintaining adequate spacing and line widths for each trace. In addition, the lower traces are connected to bonding pads on the surface of the first substrate and are thus provided in the same plane as the upper traces. Testing of and access to both upper and lower traces is thus simplified.
摘要:
Consistent with the present disclosure, an arrayed waveguide grating (AWG) is provided that includes first inputs and second inputs. Each of the first inputs receives a corresponding one of a plurality of first optical signals, each of which has a corresponding one of a plurality of wavelengths. Second inputs are also provided, such that each second input is preferably provided between two adjacent first inputs. Each of the second inputs receives a corresponding one of a plurality of second optical signals, and each of the second plurality of optical signals has a corresponding one of those wavelengths. Each of the first plurality of optical signals, however, has a first polarization and each of the second plurality of optical signals has a second polarization different than the first polarization. Since the first optical signals are supplied through AWG inputs that are offset from the inputs that receives second optical signals, the first optical signals are supplied at a first AWG output that is spaced from a second AWG output that supplies the second optical signals. The second optical signals are supplied through the second output even though the second optical signals have the same (or substantially the same) wavelengths as the first optical signals. Accordingly, a single AWG may be provided to multiplex both first and second optical signals, thereby simplifying PIC design.
摘要:
A monolithic receiver photonic integrated circuit (RxPIC) chip includes a plurality of optical signal channels together with other active elements integrated on a semiconductor chip, which chips further include a wavelength selective decombiner comprising a supergrating or an Echelle grating which provides for a more compact chip compared to an integrated on-chip arrayed waveguide grating (AWG) functioning as a wavelength selective decombiner.