Abstract: Embodiments of an optical detection apparatus are disclosed which may include one or more of a waveguide, a trench formed in the waveguide, a reflective surface, and a photodetector. The waveguide may be formed in a semiconductor substrate to propagate an optical signal received at a first end of the waveguide. The trench may also be formed in the waveguide having a first sidewall and a second sidewall, the first and second sidewalls forming first and second angles with the waveguide's propagation direction. The second sidewall may include a reflective surface formed thereon. The photodetector may be configured to receive an optical signal propagated in the waveguide, through the first sidewall and reflected from the reflective surface on the second sidewall.

Abstract: Embodiments of an optical detection apparatus are disclosed which may include one or more of a waveguide, a trench formed in the waveguide, a reflective surface, and a photodetector. The waveguide may be formed in a semiconductor substrate to propagate an optical signal received at a first end of the waveguide. The trench may also be formed in the waveguide having a first sidewall and a second sidewall, the first and second sidewalls forming first and second angles with the waveguide's propagation direction. The second sidewall may include a reflective surface formed thereon. The photodetector may be configured to receive an optical signal propagated in the waveguide, through the first sidewall and reflected from the reflective surface on the second sidewall.

Abstract: Embodiments of an optical detection apparatus are disclosed which may include one or more of a waveguide, a trench formed in the waveguide, a reflective surface, and a photodetector. The waveguide may be formed in a semiconductor substrate to propagate an optical signal received at a first end of the waveguide. The trench may also be formed in the waveguide having a first sidewall and a second sidewall, the first and second sidewalls forming first and second angles with the waveguide's propagation direction. The second sidewall may include a reflective surface formed thereon. The photodetector may be configured to receive an optical signal propagated in the waveguide, through the first sidewall and reflected from the reflective surface on the second sidewall.

Abstract: Embodiments of an optical detection apparatus are disclosed which may include one or more of a waveguide, a trench formed in the waveguide, a reflective surface, and a photodetector. The waveguide may be formed in a semiconductor substrate to propagate an optical signal received at a first end of the waveguide. The trench may also be formed in the waveguide having a first sidewall and a second sidewall, the first and second sidewalls forming first and second angles with the waveguide's propagation direction. The second sidewall may include a reflective surface formed thereon. The photodetector may be configured to receive an optical signal propagated in the waveguide, through the first sidewall and reflected from the reflective surface on the second sidewall.

Abstract: Embodiments of an optical detection apparatus are disclosed which may include one or more of a waveguide, a trench formed in the waveguide, a reflective surface, and a photodetector. The waveguide may be formed in a semiconductor substrate to propagate an optical signal received at a first end of the waveguide. The trench may also be formed in the waveguide having a first sidewall and a second sidewall, the first and second sidewalls forming first and second angles with the waveguide's propagation direction. The second sidewall may include a reflective surface formed thereon. The photodetector may be configured to receive an optical signal propagated in the waveguide, through the first sidewall and reflected from the reflective surface on the second sidewall.

Abstract: Embodiments of an optical detection apparatus are disclosed which may include one or more of a waveguide, a trench formed in the waveguide, a reflective surface, and a photodetector. The waveguide may be formed in a semiconductor substrate to propagate an optical signal received at a first end of the waveguide. The trench may also be formed in the waveguide having a first sidewall and a second sidewall, the first and second sidewalls forming first and second angles with the waveguide's propagation direction. The second sidewall may include a reflective surface formed thereon. The photodetector may be configured to receive an optical signal propagated in the waveguide, through the first sidewall and reflected from the reflective surface on the second sidewall.

Abstract: An optical transmitter includes an external cavity laser array formed in a PLC, a trench-based detector array and an AWG. The external cavity laser is formed using an array of substantially similar laser gain blocks and an array of gratings formed in waveguides connected to the gain blocks. Each grating defines the output wavelength for its corresponding external cavity laser. Each detector of the detector array includes a coupler to cause a portion of a corresponding laser output signal of the laser array to propagate through a first sidewall of a trench and reflect off a second sidewall of the trench to a photodetector. In one embodiment, the photodetector outputs a signal indicative of the power level of the reflected signal, which a controller uses to control the laser array to equalize the power of the laser output signals.

Abstract: External cavity laser devices provide multimode laser operation by using a wavelength selective element that produces a spectral width profile able to support multiple longitudinal laser modes. The spectral width profile, for example, may have a substantially flat response across multiple longitudinal laser modes, such that no single mode predominates. The wavelength selective elements may be gratings written in waveguides, where the grating's bandwidth as well as the laser cavity length set the number of supported longitudinal laser modes. In some examples, a tuning element may be used to adjust device operation. In further examples, a laser gain region and the wavelength selective element may be angled with respect to adjacent coupling facets to reduce reflection losses within the laser cavity.

Abstract: An optical transmitter includes an external cavity laser array formed in a PLC, a trench-based detector array and an AWG. The external cavity laser is formed using an array of substantially similar laser gain blocks and an array of gratings formed in waveguides connected to the gain blocks. Each grating defines the output wavelength for its corresponding external cavity laser. Each detector of the detector array includes a coupler to cause a portion of a corresponding laser output signal of the laser array to propagate through a first sidewall of a trench and reflect off a second sidewall of the trench to a photodetector. In one embodiment, the photodetector outputs a signal indicative of the power level of the reflected signal, which a controller uses to control the laser array to equalize the power of the laser output signals.

Abstract: An improved method of measurement of noise figure and gain of optical amplifiers is based on transforming the amplifier into an oscillator by applying optical feedback with known loss. The feedback consists of a tunable filter for wavelength control and of a variable attenuator for gain control. Measuring the output power at a given wavelength and the noise characteristics of the output signal, either with an optical spectrum analyzer or with a set of tunable filters and a power meter, provides data for full characterization of the optical amplifier. Another method is disclosed that utilizes the self-heterodyne setup and electrical spectrum analyzer to measure the spectral line width of the lasing amplifier, from which the noise figure is derived.