FIELD

The present subject-matter relates to optical systems, and more particularly to optical systems that include telescope assemblies.

INTRODUCTION

The following is not an admission that anything discussed below is part of the prior art or part of the common general knowledge of a person skilled in the art.

Satellite based telecommunication is increasingly being used to provide broadband communication across the globe. Telecommunication satellites can rapidly transmit data between locations on opposite sides of the globe, including locations on land, at sea and in the air. A number of satellite constellations are being launched in low earth orbit (e.g. One Web, Telesat LEO, Space X's Starlink, Amazon's Kuiper, etc.) to facilitate the transmission of data across the globe. There is an ongoing need to improve the communication capabilities of satellites used in telecommunication.

SUMMARY

The following introduction is provided to introduce the reader to the more detailed discussion to follow. The introduction is not intended to limit or define any claimed or as yet unclaimed invention. One or more inventions may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures.

Satellite based telecommunications systems can provide point-to-point communication coverage across the planet. To facilitate communications over large distances, networks of satellites can be used to route communications. The satellites in these networks can be configured to communicate with neighboring satellites through optical inter-satellite links. To facilitate communication through these networks, each satellite can include multiple communication terminals (often four terminals) to provide links to multiple neighboring satellites.

In accordance with this disclosure, an optical system can be provided with a shared telescope assembly for a plurality of signal terminals. Each signal terminal may be used to transmit and/or receive signals. The plurality of signal terminals can share an optical train defined by the telescope assembly while still being capable of pointing in different directions. Each signal terminal may be independently adjustable to define the external signal transmission/acquisition direction for that terminal. Combining the optical trains for the different signal terminals can reduce the overall size and mass of the optical assembly required by the satellite. In addition, by providing a shared optical train assembly, manufacturing and testing of the optical system can be simplified.

In an aspect of this disclosure, there is provided an optical system comprising: a plurality of internal apertures, wherein each internal aperture is operable to receive a corresponding aperture-specific optical signal; a plurality of external optical assemblies, wherein each external optical assembly corresponds to one of the internal apertures, and each external optical assembly is operable to direct the aperture-specific optical signal of the corresponding internal aperture in a corresponding external direction, wherein the external direction for each external optical assembly is independently controllable; and a telescope assembly positioned between the plurality of internal apertures and the plurality of external optical assemblies, wherein the telescope assembly defines a shared optical train arranged to direct the aperture-specific optical signals between each internal aperture and the corresponding external optical assembly.

In some embodiments, the optical system may be an optical laser communication system.

In some embodiments, the shared optical train may include a parabolic mirror, and each external optical assembly may include an input sub-aperture arranged facing the same parabolic mirror so that each corresponding aperture-specific optical signal is reflected by the same parabolic mirror.

In some embodiments, the telescope assembly can define a central telescope axis, and the parabolic mirror may be concentric with the central telescope axis. In some embodiments, the parabolic mirror may be rotationally symmetric about the central telescope axis.

In some embodiments, the telescope assembly can define a central telescope axis, and the optical train may be rotationally symmetric about the central telescope axis.

In some embodiments, the optical train may include a plurality of optical elements, and the plurality of optical elements may be concentric.

In some embodiments, the optical train may include a plurality of mirrors, and the plurality of mirrors may be concentric.

In some embodiments, the optical train may include a plurality of lenses, and the plurality of lenses may be concentric.

In some embodiments, the optical train may include a plurality of mirrors, and each mirror may be rotationally symmetric.

In some embodiments, the optical train may include a plurality of lenses, and each lens may be rotationally symmetric.

In some embodiments, the optical train may include at least one lens and at least one mirror and the at least one lens and the at least one mirror may be concentric.

In some embodiments, the optical train may include at least one lens and at least one mirror and each lens and each mirror may be concentric.

In some embodiments, the telescope assembly may define a telescope field of view; and each external direction may have an angular separation from each and every other external direction that is controllable to an angular separation range greater than the telescope field of view.

In some embodiments, each external optical assembly may include an adjustable beam deflector operable to direct the corresponding aperture-specific optical signal through a corresponding external communication terminal in the corresponding external direction.

In some embodiments, the beam deflector may include a coarse pointing assembly.

It will be appreciated by a person skilled in the art that an optical system may include any one or more of the features contained herein and that the features may be used in any particular combination or sub-combination suitable for an optical system.

Other features and advantages of the present application will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the application, are given by way of illustration only and the scope of the claims should not be limited by these embodiments, but should be given the broadest interpretation consistent with the description as a whole.

