CN100401110C - Optical component set used for optical read write head and its manufacturing method - Google Patents
Optical component set used for optical read write head and its manufacturing method Download PDFInfo
- Publication number
- CN100401110C CN100401110C CNB2004100826376A CN200410082637A CN100401110C CN 100401110 C CN100401110 C CN 100401110C CN B2004100826376 A CNB2004100826376 A CN B2004100826376A CN 200410082637 A CN200410082637 A CN 200410082637A CN 100401110 C CN100401110 C CN 100401110C
- Authority
- CN
- China
- Prior art keywords
- optical
- optical elements
- write head
- read
- elements sets
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Optical Head (AREA)
- Polarising Elements (AREA)
Abstract
The present invention provides an optical component set for optical read-write heads, which does not comprise a quarter wavelength plate (QWP) and comprises a plurality of optical elements, wherein at least two optical elements are respectively provided with an optical filming for generating phase differences, so that the polarized state of light beams is changed to make emitting light become circular polarized light. The circular polarized light is emitted in an optical storage medium and finally becomes a signal beam received by a photodetector.
Description
Technical field
The relevant a kind of optical read-write device of the present invention, and particularly relevant a kind of optical read/write head.
Background technology
Store the data to CD and DVD and go up that to carry out the technology of access ripe well known with will store data on it by optical read-write device, common data write is to be undertaken by the action of optical read/write head; Is earlier laser beam to be focused on the disc data storage surface data by the principle of taking out on the disc, then will by disc surface reflected and the signal beams that produces through a photo-detector, convert electronic signal to; Experimental result confirms, is a circularly polarized light if be incident in the laser beam of discs, and then the signal beams of gained is preferable, and therefore, making the light beam that is incident in discs become a circularly polarized light just becomes one of optical design condition of optical read/write head.
Figure 1A has shown a traditional optical read/write head, and this optical read/write head comprises the laser diode 101 of DVD read-write usefulness, laser diode 103, a polar biased spectroscope (polarized beamsplitter) 105, one polar biased spectroscope 107, a catoptron (folding mirror) 109, one quarter-wave plate (the quarter wavelengh plate of CD read-write usefulness; QWP) 111 and one photo-detector 113; Laser diode 101 and 103 is that it is linear polarization state that laser beam penetrates the back in laser diode in order to the generation laser beam, that is no phase differential exists between its two vertical component (being called S-ripple, P-ripple); Polar biased spectroscope 105 and 107 is in order to polarization components different in the light beam (S-ripple and P-ripple) is done reflection or transmission; Catoptron 109 is in order to beam reflection is changed the working direction of light beam; And quarter-wave plate 111 is in order to adjust the polarization state of light beam, make between the S-ripple, P-ripple of light beam and produce phase differential, when the phase differential of S-ripple and P-ripple reach+90 degree or+during 270 degree (that is-90 degree), just can make the light beam that is incident in CD produce the phase differential of 90 degree, and then transform the light beam into circularly polarized light, to produce preferable signal beams; 113 of photo-detectors are used to receive by disc surface and are reflected and the signal beams that produces.
In addition, after 103 bright dippings of CD laser diode, orthogonal S-wave component and P-wave component are arranged, each is with I
S1With I
P1Represent its initial intensity, suppose start-up phase potential difference δ
S-P=0 °, shown in Figure 1B, when it is incident in polar biased spectroscope 107, the efficient that penetrates that S-involves the P-ripple is respectively 90% and 0%, shown in the solid line of Fig. 1 C, if when being incident in catoptron 109, the efficient that penetrates that S-involves the P-ripple is respectively 70% and 20%, shown in the solid line of Fig. 1 D, polar biased spectroscope 107 is as shown in table 1 with the characteristic of catoptron 109;
| Penetrance | The polar biased spectroscope | Catoptron |
| The S- |
90％ | 70％ |
| The P- |
0％ | 20％ |
Table 1
So the S-ripple is intensity I after 107 reflections of polar biased spectroscope
SBecome 0, and P-ripple intensity I after 107 reflections of polar biased spectroscope
P=I
P1* 90%=0.9I
P1Then the S-ripple is again through catoptron 109 reflection back intensity I
S=0 * 70%=0, and P-ripple intensity I after catoptron 109 reflections
P=0.9I
P1* 20%=0.18I
P1, then pass through polar biased spectroscope 107 and catoptron 109 after, the P-wave energy I of light beam
P=0.18I
P1, and S-wave energy I
SThen lose fully, and before light beam enters CD, can pass through quarter-wave plate 111 again, make it to become the circular polarization state, shown in Fig. 1 E.By as can be known aforementioned, make light beam become the circular polarization state though finally can reach, the complete obiteration of S-wave energy, and be not utilized.
Summary of the invention
The invention provides a kind of optical elements sets that is used for optical read/write head, do not contain quarter-wave plate (quarter wavelength plate in this optical elements sets; QWP), and this optical elements sets comprises several optical elements that are positioned on the light path, wherein respectively has an optical coating that changes the light beam polarization state at least two optical elements, make an emergent light of advancing become a circularly polarized light along this light path, this circularly polarized light is incident in a light memory medium, and finally becomes the signal beams that a photo-detector is received.The present invention also provides a kind of manufacture method of aforementioned optical elements sets.
Owing to do not contain the quarter-wave plate in the optical elements sets provided by the present invention, therefore, can save the cost of quarter-wave plate, also can avoid the problem that quarter-wave plate quality is bad and assembly failure caused; In addition, phase differential of the present invention is made up and is produced by the different optical element, therefore, can utilize the plated film on each optical element that the polarization state of light beam is adjusted to each optical element transmission or the higher polarization state of reflection efficiency, so, just, can obtain preferable signal intensity.
Description of drawings
Figure 1A-1E forms and each optical element performance plot for the optical element of existing optical read/write head.
Fig. 2 A-2E forms and each optical element performance plot according to the optical element of optical read/write head of the present invention.
Fig. 3 A-3D is according to the phase differential that optical elements sets produced of the present invention and the graph of a relation of light beam wavelength.
Fig. 4 is the key diagram according to optical design of the present invention.
Embodiment
Fig. 2 A is the synoptic diagram that a preferred embodiment of the present invention is used for the optical elements sets of optical read/write head, and this optical elements sets comprises the laser diode 201 of DVD read-write usefulness, the laser diode 203 of CD read-write usefulness, the polar biased spectroscope 205 of a tool optical coating 204, the polar biased spectroscope 207 of a tool optical coating 206, the catoptron 209 and a photo-detector 211 of a tool optical coating 208; Laser diode 201 and 203 is the laser beams that are used in read-write DVD and CD respectively in order to produce, polar biased spectroscope 205 and 207 is in order to polarization components different in the light beam is done reflection or transmission, catoptron 209 is in order to beam reflection is changed the working direction of light beam, polar biased spectroscope 205,207 with catoptron 209 on optical coating 204,206 and 208 can make two vertical components of light beam (be called the S-ripple, the P-ripple claims) between produce phase differential, to adjust the polarization state of light beam, when the phase differential of S-ripple and P-ripple reach+90 degree or+during 270 degree (that is-90 degree), just can make the light beam that is incident in CD become circularly polarized light; 211 of photo-detectors are used to receive by disc surface and are reflected and the signal beams that produces, and to an electronic signal of converting.
Generally speaking, the wavelength of the laser diode 201 of employed DVD read-write usefulness is 660 rice how, then can design the optical coating 204 that tool produces phase differential respectively, 206 and 208 polar biased spectroscope 205,207 with catoptron 209, the relation that makes its phase differential that produces and light beam wavelength is respectively as Fig. 3 A, shown in 3B and the 3C, so, produce the plated film 204 of phase differential through tool when laser beam, 206 and 208 polar biased spectroscope 205,207 when the catoptron 209, its phase differential sum total will be shown in Fig. 3 D, when the wavelength of laser beam is 660 how during rice, because optical coating 204,206 and 208 can make the S-ripple of laser beam and P-ripple produce θ respectively
1, θ
2And θ
3Phase differential, and make θ
1, θ
2And θ
3Satisfy following condition:
θ
1+ θ
2+ θ
3=90 ° or 270 ° (1)
Therefore, can make the light beam that is incident in CD become circularly polarized light according to optical elements sets of the present invention, the effect that is produced with the quarter-wave plate is identical, and institute is so that can save the quarter-wave plate; Person skilled in the art person can need increase and decrease the number and the kind of optical element according to it, usually the optical element of the optical read/write head that is used in has laser diode, polar biased spectroscope (polarized beam splitter), grating (grating), catoptron (folding mirror), Polarizer and collimating apparatus (collimator), produces θ to make light beam respectively
1, θ
2... equiphase is poor, and makes its sum total be+/-90 degree, to reach the purpose that produces circularly polarized light.
In addition, the present invention also can utilize the principle that produces phase differential, the light beam polarization state is transformed into transmission or the higher state of reflection efficiency, also can utilize the principle that produces phase differential, to in optical element film coated, according to required phase differential of reaching and reflection/transmission rate, remove to consider in the lump selection, the number of plies and the thickness of material category.When carrying out the design of optical element, as shown in Figure 4, can utilize following formula:
Tan2α＝[2 I
S0I
P0Cos(s，p phase shift)]/I
S0 2-I
P0 2(2)
I
S0And I
P0Represent tool to produce the optical element of plated film of phase differential respectively for the reflection/transmission intensity of light beam, (s, p phase shift) represent the optical element of plated film that tool produces phase differential for the phase differential that is produced between the S-ripple of light beam and the P-ripple, angle α represents the major axis of elliptically polarized light and the angle of S-ripple coordinate axis.
With Fig. 2 A is example, after 203 bright dippings of CD laser diode, orthogonal S-wave component and P-wave component is arranged, and each is with I
S1With I
P1Represent its initial intensity, suppose start-up phase potential difference δ
S-P=0 °, shown in Fig. 2 B, when it is incident in tool when producing the polar biased spectroscope 207 of plated film of phase differential, the efficient that penetrates that S-involves the P-ripple is respectively 90% and 0%, shown in the solid line of Fig. 2 C, if be incident in tool when producing the catoptron 209 of plated film of phase differential, the efficient that penetrates that S-involves the P-ripple is respectively 70% and 20%, shown in the solid line of Fig. 2 D, yet, in embodiments of the invention, on polar biased spectroscope 207 and the catoptron 209 optical coating 206 and 208 that can produce phase differential is arranged respectively, optical coating 206 and 208 can make respectively between S-ripple and the P-ripple produce 70 ° with 200 ° phase differential, shown in the dotted ellipse of Fig. 2 C and 2D, the characteristic of polar biased spectroscope and catoptron is as shown in table 2 respectively;
| Penetrance | The polar biased spectroscope | Catoptron |
| The S- |
90％ | 70％ |
| The P- |
0％ | 20％ |
| Phase differential δ S-P | 70° | 200° |
Table 2
So, when laser beam is incident in polar biased spectroscope 207, optical coating 206 can redistribute beam energy, and make between S-ripple and the P-ripple and to produce 70 ° phase differential, make laser beam become elliptic polarization, and transverse is adjusted near P-wave line of propagation (because P-wave reflection efficient is higher), thus, when producing the polar biased spectroscope 207 of plated film of phase differential through tool, work as δ
S-PIn the time of=70 °, Is=0.15I
S1, Ip=0.95I
P1
When next producing the catoptron 209 of plated film of phase differential, utilize same reason, phase place is designed most concentration of energy at deflection P-ripple direction, δ originally through tool
S-P=0 o'clock, the catoptron 209 that produces the plated film of phase differential to tool has not had energy to pass, even tool produce phase differential plated film catoptron 209 penetrate efficient very big also be utilize less than, if but polar biased spectroscope 207 designs that produced the plated film of phase differential through tool make phase differential is δ
S-P=70 °, Is=0.15I when tool produces polar biased spectroscope 207 bright dippings of plated film of phase differential
S1, Ip=0.95I
P1If the design tool produces the catoptron 209 of the plated film of phase differential, the phase differential δ that it is produced
S-P=200 °, the energy transfer is focused on P-ripple direction, thus, the energy behind the catoptron 207 and 209 of the plated film of whole process tool generation phase differential can become Is=0.13I
S1, Ip=0.13I
P1, I generally speaking
S1Can equal I
P1So not only the light beam integral energy can also can make the phase differential sum total be δ than using prior art to be eager to excel
S-P=70+200=270 ° or-90 °, shown in Fig. 2 E, reach circularly polarized effect, increase efficient simultaneously and cause the polarization phenomena of being wanted.
Owing on optical element, use the optical coating that produces phase differential in the optical elements sets provided by the present invention, to reach the purpose that produces phase differential, therefore do not contain the quarter-wave plate, so, can save the cost of quarter-wave plate, also can avoid the problem that quarter-wave plate quality is bad and assembly failure caused; In addition, phase differential of the present invention is made up and is produced by the different optical element, therefore, can utilize the plated film on each optical element that the polarization state of light beam is adjusted to each optical element transmission or the higher polarization state of reflection efficiency, so, just, can obtain preferable signal intensity.
Though the present invention discloses as above with preferred embodiment; yet it is not in order to limit the present invention; any person skilled in the art person without departing from the spirit and scope of the present invention; when the change that can make all equivalences or replacement, so protection scope of the present invention is when looking accompanying being as the criterion that the application's claim scope defined.
Claims (12)
1. optical elements sets that is used for optical read/write head, this optical elements sets comprises several optical elements, wherein respectively have an optical coating that produces phase differential at least two these optical elements,, make an emergent light become a circularly polarized light to change the polarized state of light beam; And in this optical elements sets, do not contain a quarter-wave plate.
2. the optical elements sets that is used for optical read/write head as claimed in claim 1 is characterized in that, this optically coated this optical element of at least one tool is a laser beam generator.
3. the optical elements sets that is used for optical read/write head as claimed in claim 1 is characterized in that, this optically coated this optical element of at least one tool is a polar biased spectroscope.
4. the optical elements sets that is used for optical read/write head as claimed in claim 1 is characterized in that, this optically coated this optical element of at least one tool is a catoptron.
5. the optical elements sets that is used for optical read/write head as claimed in claim 1 is characterized in that, this optically coated this optical element of at least one tool is a collimating apparatus.
6. the optical elements sets that is used for optical read/write head as claimed in claim 1 is characterized in that, the polarization state of the also adjustable lay the grain bundle of this optical coating, and this signal beams that this photo-detector is received has the highest signal intensity.
7. manufacture method that is used for the optical elements sets of optical read/write head, this optical elements sets comprises several optical elements, to produce a circularly polarized light; And in this optical elements sets, do not contain a quarter-wave plate; This method is included on two these optical elements at least respectively adheres to an optical coating, and this optical coating can produce phase differential, to change the polarized state of light beam, makes an emergent light become this circularly polarized light.
8. the manufacture method that is used for the optical elements sets of optical read/write head as claimed in claim 7 is characterized in that, this optically coated this optical element of at least one tool is a laser beam generator.
9. the manufacture method that is used for the optical elements sets of optical read/write head as claimed in claim 7 is characterized in that, this optically coated this optical element of at least one tool is a spectroscope.
10. the manufacture method that is used for the optical elements sets of optical read/write head as claimed in claim 7 is characterized in that, this optically coated this optical element of at least one tool is a catoptron.
11. the manufacture method that is used for the optical elements sets of optical read/write head as claimed in claim 7 is characterized in that, this optically coated this optical element of at least one tool is a collimating apparatus.
12. the manufacture method that is used for the optical elements sets of optical read/write head as claimed in claim 7 is characterized in that, the polarization state of the also adjustable lay the grain bundle of this optical coating, and this signal beams that this photo-detector is received has the highest signal intensity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100826376A CN100401110C (en) | 2004-09-22 | 2004-09-22 | Optical component set used for optical read write head and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100826376A CN100401110C (en) | 2004-09-22 | 2004-09-22 | Optical component set used for optical read write head and its manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1752774A CN1752774A (en) | 2006-03-29 |
| CN100401110C true CN100401110C (en) | 2008-07-09 |
Family
ID=36679713
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100826376A Expired - Fee Related CN100401110C (en) | 2004-09-22 | 2004-09-22 | Optical component set used for optical read write head and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100401110C (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58169351A (en) * | 1982-03-31 | 1983-10-05 | Pioneer Video Corp | Optical information reading device |
| CN1195847A (en) * | 1997-02-27 | 1998-10-14 | 三星电子株式会社 | Optical recording/pickup head compatible with compact disk-recordable (CD-R) and digital versatile disk (DVD) using polarization beam splitter |
| US20020021494A1 (en) * | 2000-08-18 | 2002-02-21 | Delta Electronics, Inc. | Optical device |
| CN1430219A (en) * | 2002-01-04 | 2003-07-16 | 财团法人工业技术研究院 | Multi-wavelength optical read and write head |
-
2004
- 2004-09-22 CN CNB2004100826376A patent/CN100401110C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58169351A (en) * | 1982-03-31 | 1983-10-05 | Pioneer Video Corp | Optical information reading device |
| CN1195847A (en) * | 1997-02-27 | 1998-10-14 | 三星电子株式会社 | Optical recording/pickup head compatible with compact disk-recordable (CD-R) and digital versatile disk (DVD) using polarization beam splitter |
| US20020021494A1 (en) * | 2000-08-18 | 2002-02-21 | Delta Electronics, Inc. | Optical device |
| CN1430219A (en) * | 2002-01-04 | 2003-07-16 | 财团法人工业技术研究院 | Multi-wavelength optical read and write head |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1752774A (en) | 2006-03-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6366548B1 (en) | Optical pickup having two laser beam sources having wave lengths different from each other and optical device including the optical pickup | |
| US5013107A (en) | Polarization selective holographic optical element | |
| US20090257339A1 (en) | Optical head device and optical information recording or reproducing apparatus | |
| CN101853675B (en) | Optical pickup device | |
| US20080285392A1 (en) | Optical information recording method, optical information reproducing method, optical information recording apparatus and optical information reproducing apparatus | |
| US20050237902A1 (en) | Optical disk apparatus | |
| US5974020A (en) | Two-wavelength laser pick-up head for a DVD | |
| US4993789A (en) | Dual wavelength polarization selective holographic optical element | |
| KR20010088348A (en) | Light pick up arraratus and light receiving method thereof | |
| JP3377334B2 (en) | Optical head device | |
| CN100401110C (en) | Optical component set used for optical read write head and its manufacturing method | |
| KR100494475B1 (en) | Optical pick-up and optical write and read apparatus using thereof | |
| JPH10214431A (en) | Optical head device | |
| US20060039265A1 (en) | Pickup module with coating layer | |
| Katayama et al. | Dual wavelength optical head for 0.6 mm and 1.2 mm substrate thicknesses | |
| US7417936B2 (en) | Optical pickup reducing noise and polarization changer | |
| JP2002123952A (en) | Optical pickup device and optical disk driver | |
| US20060118704A1 (en) | Optical pickup device and optical element | |
| CN104813397B (en) | Light belt pickup unit with holographic optical elements (HOE) | |
| JPS62197933A (en) | Optical pickup | |
| JP3728082B2 (en) | Optical pickup | |
| JPH083906B2 (en) | Optical head device | |
| JP4201196B2 (en) | Optical head device and optical disk device | |
| JP4148287B2 (en) | Optical lens and diffraction lens, optical head device, optical information device | |
| JPH0750032A (en) | Optical head device and optical information device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20081219 Address after: Taiwan Taipei City Beitou District China meritorious Street No. 76 5 floor Co-patentee after: Mingshuo Comp (Suzhou) Patentee after: Harmony with Polytron Technologies Inc Address before: Beitou District of Taiwan city of Taipei Province Li Road No. 150 4 floor Patentee before: Huashuo Computer Co., Ltd. |
|
| ASS | Succession or assignment of patent right |
Owner name: HESHUO JOINT SCIENCE AND TECHNOLOGY CO., LTD. Free format text: FORMER OWNER: HUASHUO COMPUTER CO LTD Effective date: 20081219 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20090710 Address after: Beitou District of Taiwan city of Taipei province meritorious Street No. 76 5 floor Co-patentee after: Kaishuo Computers (Suzhou) Co., Ltd. Patentee after: Harmony with Polytron Technologies Inc Address before: Beitou District of Taiwan city of Taipei province meritorious Street No. 76 5 floor Co-patentee before: Mingshuo Comp (Suzhou) Patentee before: Harmony with Polytron Technologies Inc |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080709 Termination date: 20110922 |