Coherent Modulation-Free Photonic Active (COMPACT) Stabilization Specification
US20260135620A1
Abstract
COherent Modulation-free Photonic ACTive (or “COMPACT”) Stabilization is described. The COMPACT stabilization provides significant improvement relative to a traditional Pound-Drever-Hall (PDH) technique, which may be used to lock light sources (such as lasers) to optical cavities (and/or locking optical cavities to light sources). COMPACT stabilization may include or otherwise utilize a second light source that functionally replaces an external microwave source of existing PDH stabilizers. COMPACT stabilization may provide noiseless gain to the locking error signal, thereby increasing the sensitivity and improving the performance of the stabilizer.
Description (excerpt)
GOVERNMENT INTEREST The invention described herein may be manufactured, used and licensed by or for the U.S. Government. BACKGROUND OF THE INVENTION Existing laser stabilization solutions require elements such as an external microwave source to modulate the laser. Thus, there is a need for stabilization that is able to be implemented without using an external modulation source. BRIEF SUMMARY OF THE INVENTION Some embodiments of the invention provide COherent Modulation-free Photonic ACTive (or “COMPACT”) Stabilization. The COMPACT stabilization provides significant improvement relative to a traditional Pound-Drever-Hall (PDH) technique, which may be used to lock lasers to optical cavities (and/or locking optical cavities to lasers). COMPACT stabilization of some embodiments may include or otherwise utilize a second laser that functionally replaces an external microwave source of existing PDH stabilizers. COMPACT stabilization may provide noiseless gain to the locking error signal, thereby increasing the sensitivity and improving the performance of the stabilizer. COMPACT stabilization of some embodiments may utilize a real-time measurement of the frequency difference between a first laser and a frequency reference point established via a frequency-dependent optical element (FDOE). The measured frequency difference may be used to match (i.e., be equal to) the frequency of the laser to that of the FDOE (or vice-versa). COMPACT stabilization allows the real-time measurement to be performed without modulation of the first laser by the introduction of the second laser, which may act as a local oscillator. The components and operation of a COMPACT stabilization device, system, set(s) of component(s), and/or other type of implementation (herein referred to as “COMPACT stabilizers”) may provide a number of advantages over a traditional PDH system. In contrast to previous implementations of PDH for example, COMPACT stabilization does not achieve optical phase sensitive detection by modulating the input laser with an external microwave source. Instead, COMPACT stabilization achieves optical phase sensitive detection by mixing the input laser with a second laser. This approach has several distinct advantages over previous implementations of PDH, including the elimination of external electronic frequency sources and modulators as well as improved sensitivity through the use of optical coherent detection with a second laser. COMPACT stabilization may be used in applications such as: physical sensors (e.g., temperature, vibration, strain, acoustic, etc.), biological sensors, chemical sensors (e.g., spectroscopy sensors), light detection and ranging (LIDAR) or radio detection and ranging (RADAR), clocks and/or frequency references in next-generation communications networks (e.g., 6G and beyond), other sensors based on detection of optical phase or frequency shifts (e.g., magnetic field sensors, gyroscopes, etc.), optical clocks, and/or other appropriate applications. COMPACT stabilization may compare the frequency of a laser to a frequency reference point that is generated by an FDOE. Using COMPACT stabilization, the laser frequency may be locked to frequency reference point of the FDOE or the frequency reference point of the FDOE can be locked to the laser frequency. The term “FDOE” is used herein in a generalized sense, and may refer to any optical device that imparts a frequency-dependent response (e.g., an optical delay line, a ring resonator, an optical grating, etc.). BRIEF DESCRIPTION OF DRAWINGS The novel features of the disclosure are set forth in the appended claims. However, for purposes of explanation, several embodiments are illustrated in the following drawings. FIG. 1 illustrates a schematic block diagram of a first coherent modulation-free photonic active (COMPACT) stabilizer of one or more embodiments described herein; FIG. 2 illustrates a schematic block diagram of a second COMPACT stabilizer of one or more embodiments described herein; FIG. 3 illustrates a schematic block diagram of a third COMPACT stabilizer of one or more embodiments described herein; FIG. 4 illustrates a schematic block diagram of a fourth COMPACT
Filing details
- Inventors
- James P. Cahill
- Assignee
- U.S. Government, as Represented by Secretary of the Army
- Filed
- Nov 14, 2024
- Granted
- Application pending
Bibliographic data and excerpted text sourced from Google Patents (public record) as part of IP TechMatch's current-filings monitor. This filing is not part of the 2019 historical archive. For the authoritative full text, drawings, and legal status, see the source links above or consult USPTO records directly.