Methods for manufacturing volume Bragg grating elements
Methods for recording volume Bragg grating structures having a target wavelength are disclosed. Such a method may include providing a photosensitive recording medium, bringing a first face of the recording medium into contact with a face of a prism, the prism being made of a material that is transparent at a recording wavelength, and recording a Bragg grating onto the recording medium by exposing the prism to an incident light wave at the recording wavelength.
1. A method for recording a volume Bragg grating structure having a target wavelength, the method comprising:
providing a photosensitive recording medium;
bringing a first face of the recording medium into contact with a face of a prism, the prism being made of a material that is transparent at a recording wavelength;
recording a Bragg grating onto the recording medium by exposing the prism to an incident light wave at the recording wavelength; and
bringing an auxiliary piece of transparent material into contact with the first face of the recording medium such that a standing wave fringe pattern is formed within the recording medium due to a total internal reflection of the incident light on a face of the auxiliary piece of transparent material.
2. A method according to claim 1 , wherein the recording wavelength is shorter than the target wavelength.
3. A method according to claim 1 , wherein the recording medium is photosensitive at the recording wavelength.
4. A method according to claim 1 , further comprising:
bringing the first face of the recording medium into contact with the first face of the prism such that the incident light can enter into the recording medium at a prescribed angle.
5. A method according to claim 1 , further comprising:
adjusting an angle between the prism and the incident light wave during exposure of the recording medium to the incident light to produce a filter with a desired spectral response.
6. A method according to claim 1 , further comprising:
adjusting an angle between the prism and the incident light wave during exposure of the recording medium to the incident light to produce a filter with a location-dependent target wavelength.
7. A method according to claim 1 , further comprising:
bringing a second face of the recording medium into contact with a face of a second prism, the prism being made of a material that is transparent at the recording wavelength; and
recording the Bragg grating onto the recording medium by exposing the second prism to a second incident light wave at the recording wavelength.
8. A method according to claim 1 , further comprising:
rotating the prism and the recording medium to produce a first half of a symmetric filter in the recording medium.
9. A method according to claim 8 , further comprising:
providing a second photosensitive recording medium;
bringing a first face of the second recording medium into contact with a face of a prism, the prism being made of a material that is transparent at a recording wavelength;
recording a Bragg grating onto the second recording medium by exposing the prism to an incident light wave at the recording wavelength; and
rotating the prism and the second recording medium to produce a second half of the symmetric filter in the second recording medium.
10. A method according to claim 9 , further comprising:
bringing the first and second recording media into direct contact to form a continuous optical path from the first medium into the second medium.
11. A method according to claim 1 , further comprising:
placing a mask proximate an entrance face of the prism, the mask having a slit and preventing exposure of the entrance face of the prism to the incident light wave except through the slit.
12. A method according to claim 11 , further comprising:
translating the mask along an axis relative to the entrance face of the prism,
rotating the prism and the recording medium relative to the incident light wave such that a grating is formed within the recording medium, the grating having varied periods in various locations within the recording medium.
13. A method according to claim 1 , further comprising:
placing an optical element proximate an entrance face of the prism, said optical element receiving said incident light wave and producing a curved wavefront that is incident on an entrance face of the prism,
wherein a grating having a spatially varying period is recorded within the recording medium.
14. A method for recording a volume Bragg grating structure having a target wavelength, the method comprising:
providing a photosensitive recording medium;
bringing a first face of the recording medium into contact with a face of a prism, the prism being made of a material that is transparent at a recording wavelength;
recording a Bragg grating onto the recording medium by exposing the prism to an incident light wave at the recording wavelength;
rotating the prism and the recording medium to produce a first half of a symmetric filter in the recording medium;
providing a second photosensitive recording medium;
bringing a first face of the second recording medium into contact with a face of a prism, the prism being made of a material that is transparent at a recording wavelength;
recording a Bragg grating onto the second recording medium by exposing the prism to an incident light wave at the recording wavelength; and
rotating the prism and the second recording medium to produce a second half of the symmetric filter in the second recording medium.
15. A method for recording a volume Bragg grating structure having a target wavelength, the method comprising:
providing a photosensitive recording medium;
bringing a first face of the recording medium into contact with a face of a prism, the prism being made of a material that is transparent at a recording wavelength;
recording a Bragg grating onto the recording medium by exposing the prism to an incident light wave at the recording wavelength; and
placing a mask proximate an entrance face of the prism, the mask having a slit and preventing exposure of the entrance face of the prism to the incident light wave except through the slit.
16. A method for recording a volume Bragg grating structure having a target wavelength, the method comprising:
providing a photosensitive recording medium;
bringing a first face of the recording medium into contact with a face of a prism, the prism being made of a material that is transparent at a recording wavelength;
recording a Bragg grating onto the recording medium by exposing the prism to an incident light wave at the recording wavelength; and
placing an optical element proximate an entrance face of the prism, said optical element receiving said incident light wave and producing a curved wavefront that is incident on an entrance face of the prism,
wherein a grating having a spatially varying period is recorded within the recording medium.