摘要:
An analog circuit including a voltage divider for providing a first voltage corresponding to an actual temperature of said thermal tuning element of the laser; an analog comparator generating an analog output current for comparing the first voltage with a reference voltage, the reference voltage being representative of a temperature of said thermal tuning element of the laser corresponding to a desired wavelength of the laser; and a heating element thermally coupled to said thermal tuning element, wherein the analog comparator increases said analog current to the heating element, when the first voltage is less than the reference voltage; and decreases said analog current to the heating element, when the first voltage is larger than the second reference voltage.
摘要:
A method comprising forming two or more frames from a first wafer, forming two or more etalons from a second wafer, disposing a resistive thermal device on each of the two or more frames, dicing the first wafer and the second wafer, and bonding each of the frames to a corresponding one of the etalons to form optical subassemblies of optical filters.
摘要:
Briefly, in accordance with one or more embodiments, a thermally controlled optical filter comprises a frame coupled to an etalon where the frame includes a resistive thermal device disposed on the frame to obtain thermal measurements of the etalon during operation. The frame may be generally L-shaped or generally square-shaped. The frame may include a fillet that is generally planar, generally beveled or trapezoidal, or generally circular in shape. A heater may be additionally disposed on the frame. The etalon and frame subassembly may be bonded to a micro hot plate that is capable of heating the etalon to an operational temperature.
摘要:
Briefly, in accordance with one or more embodiments, a thermally controlled optical filter comprises a frame coupled to an etalon where the frame includes a resistive thermal device disposed on the frame to obtain thermal measurements of the etalon during operation. The frame may be generally L-shaped or generally square-shaped. The frame may include a fillet that is generally planar, generally beveled or trapezoidal, or generally circular in shape. A heater may be additionally disposed on the frame. The etalon and frame subassembly may be bonded to a micro hot plate that is capable of heating the etalon to an operational temperature.
摘要:
According to embodiments of the present invention, an external cavity laser includes one or more tuning elements. At least one modulated voltage signal or dither is used to lock the transmission peak of the two tuning elements to each other. The wavelength of the laser also may lock onto the lock transmission peaks. In embodiments in which two dither signals are used, the dither signals may be orthogonal to or independent of each other. The two dither signals may produce two control signals to align the transmission peak of one filter to the transmission peak of another filter and the lasing mode of the laser to the aligned filters.
摘要:
Optical transponders incorporating an optical dispersion compensator (“ODC”) to perform an adjustable, frequency dependent correction of an optical signal are described and claimed. The ODC is adjusted by a feedback controller that responds to information from at least one signal analyzer. Systems using similar ODC-equipped optical transponders are also described and claimed.
摘要:
A chip carrier having improver thermal properties, wherein the chip carrier may be formed having waist section, and a first transverse end portion joined to the waist section. A first surface of the carrier being configured to receive a chip thereon, and a second surface of the carrier configured to be coupled to a thermal control unit to provide cooling of the carrier and chip. The chip carrier may have a second transverse end portion joined to the waist portion in certain embodiments.
摘要:
An external cavity laser apparatus and method wherein wavelength or channel selection is carried independently from adjustment of external cavity optical path length. The apparatus comprises a wavelength or channel selector tuner and an external cavity tuner, wherein the wavelength tuner is uncoupled from the external cavity tuner. The tuning mechanisms for wavelength selection and cavity optical path length are configured to operate independently or orthogonally with respect to each other. The wavelength tuner may operate according to a first, channel selection signal, while the external cavity tuner operates according to a second, external cavity adjustment signal. The wavelength tuner and external cavity tuner may operate under the control of the same, or of separate controllers. The channel selection signal may be derived from a look-up table of adjustment parameter data accessed by a controller, and the external cavity adjustment signal may be derived from an error signal from a detector configured to measure external cavity loss.
摘要:
A servo or control technique and apparatus for performing wavelength locking employs the phase-shift modulation scheme to adjust one or more optical elements in the laser cavity to lock the lasing frequency toward a desired channel frequency. A controller comprises a high bandwidth mode and a low bandwidth mode. When initially locking to a new channel, the high bandwidth controller mode may be used to supply more energy to drive an actuator to achieve faster seeking. When an error signal approaches within a pre-defined threshold of zero error, the controller may be switched to a lower bandwidth mode supplying less power to the actuator to softly approach the target frequency and avoid overshoot. The lower bandwidth controller mode may keep the noise level lower and provide better frequency tracking stability to the tunable laser.
摘要:
External cavity lasers apparatus and methods that allow fast tuning, high wavelength stability, low cavity losses, and form factors that are comparable to solid state, fixed wavelength lasers. The apparatus comprise a gain medium emitting a light beam, a tunable wavelength selection element positioned in the light beam and configured feed back light of a selected wavelength to the gain medium, and a microelectromechanical systems (MEMS) actuator element operatively coupled to the tunable wavelength selection element. The MEMS actuator element may be configured to actuate the tunable wavelength selection element according to a first degree of freedom to select the wavelength of the feedback to the gain medium, and to actuate the actuate the tunable wavelength selection element according to a second degree of freedom to provide phase control of the feedback. The MEMS actuator element and tunable wavelength selection element may additionally be configured such that actuation of the tunable wavelength selection element with respect to a third degree of freedom provides a selectable level of attenuation of the feedback to the gain medium.