Abstract: A frequency swept laser source that generates an optical signal that is tuned over a spectral scan band at single discrete wavelengths associated with longitudinal modes of the swept laser source. Laser hopping over discrete single cavity modes allows long laser coherence length even under dynamic very high speed tuning conditions. A ramp drive to the laser is used to linearize laser frequency tuning. A beam splitter is used to divide the optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample. A detector system detects the optical signal from the reference arm and the sample arm for generating depth profiles and images of the sample.

Abstract: A frequency swept laser source that generates an optical signal that is tuned over a spectral scan band at single discrete wavelengths associated with longitudinal modes of the swept laser source. Laser hopping over discrete single cavity modes allows long laser coherence length even under dynamic very high speed tuning conditions. A ramp drive to the laser is used to linearize laser frequency tuning. A beam splitter is used to divide the optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample. A detector system detects the optical signal from the reference arm and the sample arm for generating depth profiles and images of the sample.

Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.

Abstract: An external cavity laser has a mirror-based resonant tunable filter, such as a Fabry Perot tunable filter or Gires-Tournois interferometer tuning element, with the tunable filter being preferably used as a laser cavity mirror. A mirror-based resonant tunable filter is selected in which the spectral response in reflection has an angular dependence. A tilt scheme is used whereby by selecting an appropriate angle between the filter's nominal optical axis and the cavity optical axis, a narrowband peak spectral reflection is provided to the laser cavity. This tunable narrowband spectral reflection from the filter is used to lock and tune the laser output wavelength.

Abstract: An optical resonator including is designed is to degrade the ability of the resonator to support suppress higher order transverse spatial modes. The inventive optical resonator forces Higher higher order transverse modes to be fundamentally unstable in the inventive optical resonator, ultimately achieving ultimately to achieving single transverse mode resonator operation. Specifically, the bounded phase deflection mirror shape or intracavity lens profile is tailored to confine the fundamental mode while rendering the higher order modes unstable. This has application in MEMS/MOEMS optical resonator devices by suppressing the side modes and increasing the side mode suppression ratio (SMSR), as well as improving SMSR tolerance to device external alignment, for example. This also has application to achieving single transverse mode operation in laser resonators, such as in semiconductor vertical-cavity surface-emitting lasers (VCSEL).

Abstract: A multi semiconductor source tunable spectroscopy system has two or more semiconductor sources for generating tunable optical signals that are tunable over different spectral bands. The system enables the combination of these tunable signals to form an output signal that is tunable over a combined band including these individual spectral bands of the separate semiconductor sources. The system further compensates for spectral roll-off associated with the semiconductor sources. Specifically, near the limits of the semiconductor sources' spectral bands, the power in the tunable signal tends to degrade or decrease. The system compensates for this roll-off using drive current control, attenuators, or electronic compensation.

Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.

Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.

Abstract: A semiconductor source spectroscopy system controls optical power variation of the tunable signal due to polarization dependent loss in the system and thus improves the noise performance of the system. It relies on using polarization control between the source and the sample and/or the sample and the detector. In one example, the source has a semiconductor optical amplifier and an intracavity tunable element for generating a tunable optical signal for illuminating a sample. The tunable optical signal is spectrally tuned over a scan band of the spectroscopy system by operation of the intracavity tunable element.

Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.

Abstract: A wavelength measurement system uses birefringent material waveplate, thereby producing a substantially sinusoidal spectral response. As a result, the responses of multiple birefringent filters can be combined to yield a filter system with a periodic frequency response that has an additive wavelength resolution that is spectrally stable. That is, the wavelength measurement system does not have regions where wavelength resolution is degraded. In one implementation, a waveplate system 112 is used, placed between two blocks of birefringent material 110 and 114. A quadrant detector 116 is used to detect the intensities of the resulting four beams.

Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.

Abstract: An optical resonator is designed to suppress higher order transverse spatial modes. Higher order transverse modes in the inventive optical resonator are forced to be unstable, and ultimately achieving single transverse mode resonator operation. Specifically, the mirror shape or intracavity lens profile is tailored to bound the lower order modes while rendering the higher order modes unstable. This has application in MEMS/MOEMS devices by reducing side mode suppression ratio (SMSR) dependence on alignment tolerances, for example.

Abstract: An optical resonator including is designed is to degrade the ability of the resonator to support suppress higher order transverse spatial modes. The inventive optical resonator forces Higher higher order transverse modes to be fundamentally unstable in the inventive optical resonator, ultimately achieving ultimately to achieving single transverse mode resonator operation. Specifically, the bounded phase deflection mirror shape or intracavity lens profile is tailored to confine the fundamental mode while rendering the higher order modes unstable. This has application in MEMS/MOEMS optical resonator devices by suppressing the side modes and increasing the side mode suppression ratio (SMSR), as well as improving SMSR tolerance to device external alignment, for example. This also has application to achieving single transverse mode operation in laser resonators, such as in semiconductor vertical-cavity surface-emitting lasers (VCSEL).

Abstract: A wavelength measurement system uses birefringent material waveplate, thereby producing a substantially sinusoidal spectral response. As a result, the responses of multiple birefringent filters can be combined to yield a filter system with a periodic frequency response that has an additive wavelength resolution that is spectrally stable. That is, the wavelength measurement system does not have regions where wavelength resolution is degraded. In one implementation, a waveplate system 112 is used, placed between two blocks of birefringent material 110 and 114. A quadrant detector 116 is used to detect the intensities of the resulting four beams.

Abstract: A wavelength measurement system uses birefringent material waveplate, thereby producing a substantially sinusoidal spectral response. As a result, the responses of multiple birefringent filters can be combined to yield a filter system with a periodic frequency response that has an additive wavelength resolution that is spectrally stable. That is, the wavelength measurement system does not have regions where wavelength resolution is degraded. In one implementation, a waveplate system 112 is used, placed between two blocks of birefringent material 110 and 114. A quadrant detector 116 is used to detect the intensities of the resulting four beams.

Abstract: A wavelength measurement system uses birefringent material waveplate, thereby producing a substantially sinusoidal spectral response. As a result, the responses of multiple birefringent filters can be combined to yield a filter system with a periodic frequency response that has an additive wavelength resolution that is spectrally stable. That is, the wavelength measurement system does not have regions where wavelength resolution is degraded. In one implementation, a waveplate system 112 is used, placed between two blocks of birefringent material 110 and 114. A quadrant detector 116 is used to detect the intensities of the resulting four beams.

Abstract: An optical resonator is designed to suppress higher order transverse spatial modes. Higher order transverse modes in the inventive optical resonator are forced to be unstable, and ultimately achieving single transverse mode resonator operation. Specifically, the mirror shape or intracavity lens profile is tailored to bound the lower order modes while rendering the higher order modes unstable. This has application in MEMS/MOEMS devices by reducing side mode suppression ratio (SMSR) dependence on alignment tolerances, for example.

Abstract: A tunable filter system comprises a signal source providing a WDM having multiple channels, or other signal requiring spectral analysis, within a spectral signal band. A reference signal source is also provided that generates a reference signal with spectral features, such as narrow spectral lines, that are located within a spectral reference band. A tunable filter functions as a band pass filter in transmission and a notch filter in reflection. It is controlled to filter both the reference signal and the WDM signal. A transmission detector is provided to detect the signal transmission through the tunable filter and a return detector is provided to detect the signal that is returned from the filter. Embodiments of the invention rely on a characteristic of a class of tunable filters, such as Fabry Perot etalons, in which light that is not transmitted through the filter is reflected. Thus, while the tunable filter appears as a band pass filter in transmission, it functions as a notch filter in reflection.

Abstract: A semiconductor laser system includes a reflector on the lid that directs light emitted from the front facet to the monitoring diode. Thus, even when the diode is installed behind the semiconductor laser chip, and as a result receives back facet light, the ratio of front facet to back facet light received by the monitoring diode is increased due to the operation of the reflector. This configuration improves power tracking in Bragg grating stabilized semiconductor laser systems, for example.