SPECTRAL SPLITTER DEVICE

Abstract

Disclosed is a spectral splitter device for transforming at least one initial light beam coming from a light source into more than two light beams, or vice versa, which includes: a first polarising beam splitter that splits the initial light beam into two orthogonally polarised beams; two optical elements respectively penetrated by the two orthogonally polarised beams; and a second polarising beam splitter and a third polarising beam splitter which split the two orthogonally polarised light beams into four respective output beams. Each of the two optical elements is birefringent and their birefringence depends on wavelength.

Claims

1. Spectral splitter device for transforming at least an initial light beam coming from a light source into more than two light beams or vice versa, the device comprising: a first polarization beam splitter, which splits said initial light beam into two orthogonally polarized beams; two optical elements, passed through respectively by said two orthogonally polarized beams; and a second and a third polarization beam splitter, which, in turn, split the two orthogonally polarized light beams into four respective output beams, wherein each of these optical elements is birefringent and the birefringence of both elements is wavelength dependent.

2. Spectral splitter device; according to claim 1, wherein the light of the four output light beams obtained mutually have at least one of the orthogonal polarization states or different wavelengths.

3. Spectral splitter device; according to claim 2, wherein the initial light beam passes through a birefringent and dispersive optical element before entering the first polarization beam splitter.

4. Spectral splitter device; according to claim 2, wherein the initial light beam passes through a previous polarization beam splitter before entering the first polarization beam splitter.

5. Spectral splitter device; according to claim 2, wherein the initial light beam passes through a partially reflecting mirror before entering the pre-polarizing beam splitter or a birefringent optical element.

6. Spectral splitter device; according to claim 1, wherein at least one of the four output beams passes through a third optical element which is birefringent and/or dispersive.

7. Spectral splitter device; according to claim 1, comprising more than one individual light source that generate the four output beams, combining them in a single beam when a reverse path is applied to said beams.

8. Spectral splitter device; according to claim 7, wherein said individual light sources obtain feedback from the partially reflecting mirror.

9. Spectral splitter device; according to claim 1, comprising a means of individual mutual control of the optical delay and/or dispersion of the first and second optical elements, and, if applicable, of a birefringent and dispersive optical element.

10. Spectral splitter device according to claim 9, wherein each individual optical element comprises birefringent dispersive crystals of integer multiples of a basic thickness and an additional phase delay comprising any one or a combination of: a single retarder plate or a combination of multiple retarder plates, supports for individual tilting of the optical elements to adjust the delay, Babinet-Soleil wedges, a liquid crystal element with a delay controlled by its manufacturing process or an electric field.

11. Spectral splitter device; according to claim 9, wherein each individual optical element comprises at least two parts with a slight wedge, so that the effective thickness can be adjusted by moving the two parts with respect to each other.

12. Spectral splitter device; according to claim 1, wherein the light source or sources are a laser diode, a semiconductor laser with or without low reflectivity, an LED, a laser bar or a bar stack.

13. Spectral splitter device; according to claim 9, wherein the light sources are a matrix and some of the polarizers are displacers.

Description

DESCRIPTION OF THE DRAWINGS

[0044] To complement the description being made and in order to assist in a better understanding of the characteristics of the invention, this description is accompanied, as an integral part of the same, by drawings in which the following has been represented for illustrative and non-limiting purposes:

[0045] FIG. 1. shows a schematic representation of an example of implementation of the spectral splitter device, showing the main parts and elements it comprises, as well as its arrangement.

[0046] FIG. 2. shows a schematic representation of the spectral splitter device, in this case implemented as a beam combiner, showing the arrangement of its parts.

[0047] FIG. 3. shows a top view of an embodiment example of the device as a beam combiner on an optical plate, showing the main parts and elements it comprises, as well as their arrangement, the different light beams being represented by dotted lines.

[0048] FIGS. 4 and 5. show two perspective views of an embodiment example of the assembly of a laser diode, with passive cooling and active cooling respectively, as an example of the light source comprising the spectral divider device object of the invention, showing its general configuration.

[0049] FIGS. 6 and 7 show perspective views of the laser diodes with passive cooling and active cooling, shown in FIGS. 1 and 2, in this case represented on a base using water as the cooling medium.

[0050] FIGS. 8 and 9 each show perspective views of the laser diodes with passive cooling and active cooling, mounted on their base using water as the cooling medium and shown in the preceding figures, in this case including their respective circular lens adjustments.

[0051] And figure number 10. shows a perspective view of an example of the mounting of the optical element on an inclined support.

PREFERRED EMBODIMENT OF THE INVENTION

[0052] In view of the aforementioned figures, and in accordance with the numbering adopted, it can be appreciated therein a non-limiting embodiment example of the spectral splitter device of the invention, more specifically an example as a laser optical device, which comprises what is indicated and described in detail below.

[0053] Thus, as seen in FIG. 1, the spectral splitter device (1) of the invention for transforming an initial light beam (R0), coming from a light source (F), into more than two light beams, essentially comprises: [0054] a first polarization beam splitter (P1), which splits said initial light beam (R0) into two orthogonally polarized beams (R1 and R2); [0055] two optical elements (O1 and O2), passed through respectively by the above two orthogonally polarized beams (R1 and R2); and [0056] a second and a third polarization beam splitter (P21 and P22), which, in turn, split the two orthogonally polarized light beams (R1 and R2) into four respective output beams (R11 and R12) and (R21 and R22),

[0057] with each of these optical elements (O1 and O2) being birefringent and the birefringence of both elements being wavelength dependent.

[0058] Preferably, the light from the four output light beams (R11 and R12) and (R21 and R22) obtained mutually has at least one of the orthogonal polarization states or different wavelengths.

[0059] Preferably, the initial light beam (R0) passes through a prior birefringent dispersive optical element (O0) before entering the first polarization beam splitter (P1).

[0060] Alternatively, the initial light beam (R0) passes through a prior polarization beam splitter (P0) before entering the first polarization beam splitter (P1).

[0061] And, optionally, the initial light beam (R0) passes through a partially reflecting mirror (M) before entering the aforementioned prior polarization beam splitter (P0) or the prior birefringent optical element (O0).

[0062] In any case, preferably, at least one of the four output beams (R11 and R12) and (R21 and R22) passes through a third optical element (03) which is birefringent and/or dispersive.

[0063] It should be noted that, optionally, in one embodiment, the described spectral splitter device is capable of being applied as a beam combiner when used as described above with a reverse beam path, that is, obtaining the sum of the two pairs of beams (R11 and R12) and (R21 and R22) generated by more than one individual light source (F) and combining them into a single beam (R0).

[0064] In such a case, for obtaining the beams (R), the device comprises more than one individual light source (F), preferably lasers or a laser gain means, which generate the light beams to be combined. Said individual light sources are able to obtain feedback from the partially reflecting mirror (M).

[0065] In the preferred embodiment, the spectral splitter device (1) of the invention is implemented with at least one phase delay plate for the individual mutual control of the optical delay and/or dispersion of the first and second optical elements (O1, O2) and, if applicable, of the prior optical element (O0).

[0066] Preferably, said plate is a special type of phase plate called a quarter-wave plate.

[0067] In the preferred embodiment, each individual optical element (O1, O2, O0) comprises birefringent dispersive crystals of integer multiples and of a basic thickness, and an additional phase delay comprising any one or a combination of: [0068] a single retarder plate or a combination of multiple retarder plates [0069] supports for individual tilting of the optical elements for delay adjustment [0070] Babinet-Soleil wedges [0071] a liquid crystal element with a delay controlled by its manufacturing process or an electric field.

[0072] More particularly, in the preferred embodiment, each individual optical element comprises at least two parts with a slight wedge, so that the effective thickness can be adjusted by moving the two parts with respect to each other.

[0073] Furthermore, preferably, the relative optical delay is carried out using fewer physical elements than conceptually necessary and where at least one is passed through more than once.

[0074] It should be noted that the light source(s) (F) can be a laser, semiconductor laser with or without low reflectivity, LED, laser bar, bar stack.

[0075] In addition, light sources (F) can be both either point or matrix and some of the polarizers are displacers.

[0076] Referring to FIG. 3, an example of implementation of the device of the invention on a plate (3) can be seen, in particular, an example in which four beams are combined in an output lens (L), where it can be seen how, in addition, heat sinks (D) are included.

[0077] Referring to FIGS. 3 to 9, an example of the light source (F) can be seen, specifically a semiconductor laser diode that is either passively cooled (FIG. 4) without water inside the assembly on a base (2) that has the cooling system, or actively cooled (FIG. 5) with two water channels that cool the diode.

[0078] FIGS. 6 and 7 show both options of the diode as a light source (F) in its two versions, passively and actively cooled, respectively, once mounted on the base (2) that uses water as the cooling medium.

[0079] Said base (2) is used to assemble the diode or light source (F) to the end plate (3) and is fitted with water connections (4) to fit the tubes and cool the system. The actively cooled mount shown in FIG. 7 has more robust connections to allow higher currents, although the height of both options is the same.

[0080] FIGS. 8 and 9 show the assembly of both options of the light source (F), with a passive and an active cooling system respectively, once the circular lenses (5) have been coupled, the adjustment of which does not vary as it is identical.

[0081] And finally, it can seen in FIG. 10 how, preferably, the optical element (O), which preferably is a birefringent and/or dispersing crystal, for example calcite, is mounted on a support (6) inclined at 45°.

[0082] Having sufficiently described the nature of the present invention as well as its implementation, it is considered unnecessary to extend the explanation thereof so that any person skilled in the art may understand its scope and the advantages derived therefrom.